Summer brings with it some of our favorite garden vegetables: tomatoes, peppers, cucumbers, zucchini, to name just a few. But summer also brings some of the garden’s most notorious pests whom, if left out of control, will devour those vegetables before they have a chance to make it to our table. Today I’m sharing a few of the pests we’ve encountered the most often in our zone 6b garden, and what’s worked for us to combat them naturally.
Much of this post is dedicated to methods of cultural control; meaning the surrounding environment is “tweaked” in order to avoid pests. This is accomplished through companion planting, physically removing the pests either by hand or by a forceful stream of water, introducing a natural predator, or by crop rotation.
Sometimes however, those methods don’t work well enough and as gardeners we have to make a decision to either lose the crop, or take a further step at controlling the pest. This further step usually involves a pesticide of some sort.
As a strong believer in natural gardening, I do not recommend conventional pesticides. However, as a natural gardener who is trying to earn an income from my crops, I will sometimes consider organic sprays under certain conditions. I’m including those in this post as well, along with cautions (if any) that should be taken.
Please remember: Never assume that just because a spray is marked “organic” it is safe for you, your pets, or for other beneficial insects you’d really like to have around. Always, always, always read the label and follow the instructions to the letter.
Tomato Hornworm
The very first summer that I planted a vegetable garden, I knew very little about tomatoes and even less about the pests they attracted. Imagine my surprise then, when rummaging through a jungle of tomato vines, I found myself face to face with a tomato hornworm. Thinking my beautiful tomato foliage had been invaded by tiny green aliens overnight, I was terrified.
As my gardening experience grew, I learned that this was not an alien — it was in fact a tomato hornworm.
Hornworms love to feast on the leaves of tomato plants and occasionally on those related to the tomato such as the pepper and eggplant. If left to their own devices, they can completely defoliate the plant. Not good.
Because these worms are a pretty good size and relatively easy to spot, the best way to combat them is to simply pull them off by hand. Toss them into a bucket full of warm soapy water and when they have ceased to exist, toss the bucket into your compost pile (you do have one, don’t you?).
Observe your hornworms carefully: occasionally a small parasitic wasp will lay its eggs on the worm itself, forming numerous little white cocoons all over the hornworm’s back. If you notice something like this, it is best to leave it alone. The parasitic wasps are friendly bugs and once hatched, will proceed to feast on the worm. There’s no need to get rid of this worm — just let nature do its thing.
Another idea would be to plant borage amongst your tomatoes. Borage is a lovely, easy-to-grow herb that reportedly repels the hornworm.
If you must spray: Bacillus Thuringiensis aka “BT” will handle the hornworm as well as a few other pests such as leaf hoppers and cabbage worms. BT is a naturally-occurring bacterial insect disease that reportedly will not harm other beneficial insects, animals, or humans.
Spider Mites
In our garden if we have tomatoes, we will have spider mites. It isn’t a question of “if” it is more a question of “how many” and “how soon”. Mites are typically brought on by the summer heat and cause their damage by piercing and then sucking nutrients from the leaf leaving a series of tiny brown spots on the plant. If not brought under control, they will ultimately kill your tomatoes.
Unlike the tomato hornworm, spider mites themselves are difficult to spot so one has to look for signs and symptoms: tiny, pinprick “polka dots” on the leaves, webbing similar to spider webs, and frass (mite droppings).
Another way to look for them is to hold a white sheet of paper under the leaves. Shake the plant and then watch the sheet of paper. If you have mites, they’ll slowly start moving around on the paper. They are tiny and typically red, but may be green or yellow.
One way of control is through prevention. While marigolds are a common favorite garden annual and also reported to be a great companion plant for tomatoes, they can potentially attract spider mites (at least in our area). If you must have marigolds, consider planting them a good distance away from your tomatoes.
Another means of control is to attempt to dislodge the mites with a forceful steady stream of water. Every week or so, take the hose to your tomato plants and wash them down.
Spider mites have predators — such as the lacewing. A few organic gardening suppliers offer a “herd” of these insects either as eggs to be hatched or in adult form. They can be purchased and released in your garden.
If you must spray: a pyrethrin spray can be used on a regular basis. A pyrethrin is a naturally occurring insecticide derived from the daisy. If you choose to go this route, please use with caution for two reasons:
- Pyrethrins can cause damage to beneficial insects.
- Some formulas utilize a carrier oil such as canola.
Canola is a GMO crop. I realize this can seem like a hairsplitting issue — and we’re talking about very small amounts here — but I personally feel this is something to take into consideration.
Squash Vine Borer
My least favorite villain, and one that I seem to battle in my garden every summer, is the squash vine borer. This little guy tunnels through the stem of your squash (or cucumber) plant disrupting the flow of water and nutrients. One day you will have a beautiful, healthy plant, and the next day it will appear sad and wilted.
Other tell-tale signs include a mealy mass of greenish yellow frass (excrement) oozing from the stem. Usually however, by the time you notice you have a problem, the damage is pretty well done. There isn’t a whole lot you can do to save your plant. Prevention then, is the best way to manage the borer.
Crop rotation is one way — avoid planting your squash in the same spot every year.
Floating row covers can be used to keep the borer moth from laying her eggs, but then you need to be sure that your flowers can still be pollinated or you won’t get any squash.
Another suggestion would be to plant later on in the season. Louise Riotte, author of Carrots Love Tomatoes, indicated that she had few problems with squash vine borers when squash was planted closer to the fall.
Other gardeners suggest planting new seeds every two weeks to try and stay one pace ahead of the pest.
I have had reasonably good success by wrapping the base of the plant with knee high panty hose, preventing the borer from entering. This isn’t 100% effective, and requires a lot of work, but it is worth it to get some summer zucchini.
If you do discover that you have a borer, try one or both of these things before giving up all as lost. First, slice open the stem and remove the borer, then bury the part of the stem that has been damaged. This may not save the plant, but it might perhaps prolong it enough for you to get some squash. Second, inject the stem with a shot of BT in hopes of killing the worm. Again, not always reported to be effective. In my opinion prevention and cultural control will be your best bet.
Squash Bugs
This unpleasant looking little guy draws his nourishment from the plant by piercing the tissue and thereby injecting it with a toxic substance. The result is a vine that turns black and begins to dry out. A few squash bugs may not kill a larger established plant but they can kill off small plants and small runners of larger plants, possibly decreasing the production of squash.
As with the borer, the best way to avoid the bug is prevention through crop rotation and removal of diseased squash plants. Don’t compost them.
While working about in your garden, take the time to examine your squash leaves for beady little orange squash bug eggs on the undersides. Learn to recognize them and take them out before they hatch.
Another suggestion is to arrange a few 2×4 boards alongside your squash plants. During the night, the bugs will congregate underneath. Early in the morning, before the bugs are active, they can be removed from the boards and disposed of in a pail of soapy water.
If you must spray… you really don’t have many options. Sprays that I could recommend are not effective against the squash bug. So, as with the borer, cultural control and prevention is the way to go.
A Few More Tips
Here are a few more tips for keeping things under control.
- Keep your plants strong and healthy. Make sure their proper water and nutrient needs are met. Pests are much more likely to prey upon a weak plant.
- Make it a daily habit to walk through your garden keeping a look out for signs of pests and disease. Try to take care of things as soon as you notice them, nipping potential problems right in the bud.
- Always remove any diseased plant tissue. Keeping the garden clean will also help keep pests at bay. Diseased plant tissue should not be composted.
- Learn to recognize beneficial insects, and leave them alone to do their job.
What pests do battle in your garden and how do you handle them?
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Thanks, Jenny, this is great info!
I’ve got my eye on my yellow squash. It doesn’t have any of the symptoms you mentioned above for squash bugs or borers, but it isn’t doing well — the squashes are very small, slow growing and hollow inside. I haven’t seen any pests, and I’m not sure what’s up.
You asked what pests we are battling…. Well, the day before yesterday I discovered aphids in my snap peas. Here’s a photo from Instagram.
Among the suggestions I received were to use firm pressure water to wash them off and ladybugs. So I did the water and washed them off as best I could. Then I relocated ladybugs from other parts of the garden to the peas. I haven’t seen any aphids since. I will keep doing my daily walks through the garden (I love that tip!) and hopefully it will stay aphid-free.
Again, great post. Thanks!
Wardee not having seen your squash “in person” it sounds to me like that could possibly be a lack of pollination. I’m seeing that a lot in my garden this year with both my zucchini and my cucumbers. The fruit are very small, yellow, and shriveled. This happens when the female flowers haven’t been adequately pollinated. It can be due to heat, fewer bees in the area, or a lot of wind. The only way that I know to combat that (other than planting more herbs and flowers to attract the bees) is to try self pollinating.
I hate aphids 🙁 but fortunately for us we don’t have many of them this year since we’ve moved to the country. I’m not quite sure why that is but I have noticed numerous lady bugs so they seem to be doing their job. Yes, a forceful stream of water will take care of them, and if I recall correctly once they are dislodged from the plant they can’t get back up. They do though produce several generations in one season so regular monitoring even after getting rid of them is a good thing.
Good luck with your peas! We’ve moved into the high temperatures and won’t see any more of those until fall.
Jenny — That could be it, lack of pollination. However, the zucchini right next door is doing great. It’s too early to tell on the cucumbers. Lots of blossoms but they’re just getting started. I’ll look into self-pollinating. Thank you!
Thanks again. 🙂
In my garden this year pollination is very hit and miss. I’ve had one plant that produced a gorgeous, flawless zucchini, followed by a “no-go”. The one next to it looks to be doing just fine, and several yards away I have another variety that has at least one that is also doing great. My cucumbers on the other hand are doing poorly. Lots of fruit but none are growing. None. I don’t think we’ll get any this year at all.
Jenny, I’m SO sorry to hear about your cucumbers! That would devastate me (I love cukes!). I hope mine will do okay. It is too soon to tell. And thinking about it more, I realized that I’m losing some of my little acorn squashes. They’re doing the same thing, tiny and shriveling up. Maybe that’s a pollination issue as well. 🙁
Two years ago we had a major problem with vine borers. But this year it’s been leaffooted bugs. Terrible infestation. Great post!
Ya know we have those every year, but this year I seem to have had better luck. I don’t know if it was wrapping the stems, or if we just don’t have them in this area. I’m delighted because we’ve never really been able to get a lot of zucchini.
Duct tape works great for gathering squash bug eggs or killing the nymphs if you missed any eggs. Saved my pumpkins from absolute destruction last year.
I hadn’t thought about using duct tape. That’s a great idea! Do you use it similar to how one would use a lint roller?
Pretty much 🙂 I posted about it here: http://onjustacoupleacres.blogspot.com/2012/07/how-to-kill-squash-bugs-squash-bug-eggs.html My only trouble with this method was that my little helpers liked to throw their piece of tape on the ground and I’d have to make sure I collected them all from the garden and threw them in the trash 🙂 Otherwise, it works fantastic!
Another method when the tape just isn’t quite doing the job: two rocks. Those eggs are TOUGH to squish, but between two smallish, flat rocks, they crack easily, with minimal damage to the leaf.
The dreaded Harlequin bug is my current arch nemesis, though we successfully battled cutworm too. For the cutworm, if you put a long nail or thick stick next to your seedlings, the cutworm won’t cut it because it is too tough. (I didn’t learn this until the third planting of corn was ruined! The fourth planting is doing well.) For the Harlequin, I collect the bugs almost every afternoon. The nymphs look like black orange and white lady bugs. I give them to a friend who has a toad who enjoys them. There are fewer and fewer each day, and I hardly ever see an adult one. I also look for their eggs. I am so babying the broccoli I planted. I hope it works. Of course I only have 4 broccoli plants so it is easy. Last year they devastated my kale and collards.
I’m sorry about your kale and collards. That is so frustrating when you’ve worked so hard. We had broccoli issues this year too but that was due more to weather than pests. I have heard that about using some sort of barrier for cutworms. It also works for slugs: anything sharp will keep them out of the area (supposedly)
So far, everything looks good pest-wise in our garden this year, but we had a late start to the season. Typically we have a big problem with cabbage moths, which we tried to combat with row covers but the darn things found a way to sneak in anyway! Two years ago we had a really bad infestation of cucumber beetles. Daily spraying with homemade insecticidal soap helped a lot (interesting to see that the ants carried away the dead beetles….) and crop rotation kept them from being a problem again the following year. I have been surprised that we have not yet seen a tomato hornworm, considering the large number of tomatoes we grow, but am glad to know I’ll now be prepared should they show up!
We typically have problems with cabbage moths too, but usually just in the spring and the fall. I’ve been able to keep an eye out for them, and usually just get rid of the eggs or pull off the caterpillars. I’ve had them completely wipe out my arugula though in just a matter of days.
Cucumber beetles I haven’t seen yet.
I think rosemary helps deter cabbage moths. I handpick the caterpillars too, but I happened to put my pot of rosemary near my kale and haven’t had nearly as many this year. And the kale plants where I do find them are the ones farthest from the pot. I’m not sure if it’s just a coincidence, but it seems like it’s helping.
Yes! In general most aromatic herbs do help deter some pests. I planted thyme in with my cabbages last spring and those, like you said, that were closest to the thyme were not affected. In order for it to really work though, they almost have to be touching.
Any suggestions for tomato leaf miners. Almost every one of my tomatoes succumbed to it this year. I’ve read that once you get them, you should destroy the plant but since all mine had it & there were tomatoes ripening I kept them. Will be pulling them all up this weekend.
I have not had experience personally with leafminers but I did do a little research and Neem oil may help break the life cycle by preventing the larva from reaching maturity. It is not reported to harm beneficials but just to be safe I would apply it early morning/evening when the insects are not as active. Sorry you are having to pull them all out. Are you in an area where you could start again? In my zone we can plant fall tomatoes around July 15.
Tomatoes do well with some pruning, so perhaps removing (and throwing away) the leaves that are housing the miners before they can reproduce?
This year our cucumbers were doing great. We own a high tunnel and 34 cukes (Katrina and Socrates work awesome in a tunnel BTW) were over 7 foot tall and produced a ton. In a week and a half spider mites moved in and killed most of our plants, we are down to the last 6. In a tunnel, there is little wind and no rain so mites love them. We tried spraying with water and spraying w/ dish soap and using Diamatieous Earth (I never can spell that) but they were just too many, and got the cukes. To save our tomatoes right next to them, we sprayed with that spray you mentioned, and it seemed to stop them immediately.
We also have problems with squash bugs. We use dish soap or mineral oil mixed with water or spread Diamatieos Earth, and that gets the little ones, but not so much the full grown ones. This does give the plants enough of a break to produce.
Good advice, Jenny.
Spider mites are so frustrating to deal with and here we seem to have them every year. So far my tomatoes seem to be ok so I am holding my breath. So sorry about your cucumbers.
I just ordered some diatomaceous earth from Azure standard to have on hand if we need it. I’ll keep that in mind about the squash bugs although so far our squash is doing ok pest wise.
Hello there. We were shocked this year. We are not great gardeners but have always been able to grow kale and chard and bok choy This year (one mistake is we always planted the same things in the same place) they are covered w/ insect holes and they are much smaller than usual. We have gone out 3 nights and can’t find any abundance of bugs. There are about 1/8 of the plants that have a webbing under them but not all of them. And 2 wormy like pink bugs w/ black stripes, but only 2.
Really, the plants look demolished. Any thoughts? We are about to rip them out and plant zucchini.
Are the vegetables themselves smaller than usual? Or the insect holes?
Webbing sounds to me like it could be spider mites, although I’ve never noticed them on my cole crops. I can’t exactly place the bugs you are describing, it doesn’t sound like a cabbage worm. Hmmmmmm…….
If it was me, and there was any way at all to salvage your crop, I would still try by using a floating row cover. This would help to keep some of the pests out while still allowing sunlight and water through. If there is no way it can be eaten, then yes, go ahead and take it out before whatever it is that has gotten to it spreads to something else. I wouldn’t compost that either. Hope that is helpful.
Are you in a climate where you could try again in the fall in another spot?
The plants are smaller than usual. I don’t recall ever having insects before this year.
What is a floating row cover? We have straw down now. We can eat the kale but it’s mostly stems on some of it :(.
Would you ditch the straw as well?
We are in MI so it’s hard but we were told we could plant lettuce and maybe beans (not sure about the beans) and where our tomatoes are struggling we were told to try zucchini and broccoli.
Thanks. I would appreciate whatever thoughts you have.
If your plants are smaller than usual I would venture to guess that is not an insect problem. It sounds to me like it could be something else, the weather, nutrients in the soil, it might even be the variety. I had small kale this year too. I’m thinking it had to do with the fact that we had a very long winter, that changed abruptly to a hot summer. Since you are in MI your weather is probably not as bad as ours in OK, but I throw that out there just to show you how the weather can have an impact on size.
A floating row cover is a thin piece of white fabric that can be stretched over a crop to keep pests and frost out. It is used for pest control and as a season extender. ( If you sew, it is basically like non-fusible interfacing). Any gardening supply place should offer them.
Yes. I would go ahead and ditch the straw as well. 🙁
If you decide to start over with a different crop: I would vote for the lettuce. Much easier and it can be harvested young if need be. Beans (at least for me here in a hot 6b) have been a little more difficult although I’ve had better luck with runner beans and bush beans. If I had to choose between zucchini and broccoli, I’d go with the zucchini. Much easier, in my opinion.
Have you contacted your county extension office? They might be able to help you with different varieties, etc. The Master Gardener program usually utilizes a conventional approach but there are many that support organic gardening and would be eager to help you out.
I am having trouble with rollie pollies on my squash this year. The plants look beautiful and then they just start eating through the stalks. Any ideas for what to do about them? Also, seems like my plants are producing tons of male flowers and I have only seen two females that didn’t even make it to flowering stage. Did I do something wrong during planting or should I just give it more time? They have been in the ground since the first week of May. Thanks!
I have not had problems with rollie pollies on my squash but I have seen them in the garden. I have noticed that they are typically attracted to decaying plant material. I would take a look and see if there is anything like that close to your squash plants that can be removed without disturbing your plant. Then, since they are eating through the plant, I would use the same preventive methods used for the squash borer. Purchase some inexpensive knee high panty hose and wrap the base of the stem. You might want to wear long sleeves and gloves because squash plants are prickly and tend to react with my skin. 🙁
As far as the flowers go ~ no you didn’t do anything wrong. What you are describing sounds to me like a pollination problem. The female flowers aren’t being pollinated either due to heat, wind, or lack of pollinators (bees). The plant decides they aren’t needed and drops them.
You can try to pollinate them yourself. Go out early in the morning when the flowers are open and using a paint brush or q-tip gather some of the pollen from the male and spread it to the female.
Unfortunately it is a common problem and not just with squash. I’m seeing it a lot in my garden this year with cucumbers, squash, eggplant, and tomatoes. In the case of tomatoes, it is referred to as blossom drop but the causes and remedies for it would be the same. If you want more info, I’m linking to that post using the Comment Love widget.
Keep trying! I hope that helps.
We have a couple cherry trees in our yard and this year discovered little white worms in them (my husband and children ate a ton of them first though). After some research i found out they are fruit fly larvae. I would love to know a natural pesticide free way of getting rid of them. Any ideas?
I’m sorry but I do not have first hand experience with organic pest control for cherries. I do know that it is very difficult to grow stone fruits organically however. I would recommend contacting Gardens Alive. They have products for home orchards and may be able to tell you of a cultural method or a natural product that could help with fruit flies.
Thank you!
What about neem oil? Do you recommend it or use it on anything? Thanks!
I have only recently started using neem oil sparingly on an as needed basis.
I had some okra seedlings that were being devoured before they had a chance to really establish themselves so I used two methods of trying to control whatever it was: I covered a few to protect them, and I sprayed a few with neem oil. Long term, the ones that were sprayed with the oil seem to be healthier, although all of my plants still have some damage.
I know that this is a product that is derived from the neem tree and from what I have read is not harmful to beneficial insects. The oil itself however can cause damage if it falls on, say bees, so it is best to apply it early in the morning or in the evening when they are not active.
Hi Jenny! I had commented on one of Wardee’s post and she directed me to your post to ask my question. I love all the helpful tips above and will be writing them down but wondered if you might have anything to add to my current problem. Here is my comment to Wardee….
I have a question for you. How do you control the pest in your garden? This year we planted quite a bit and have had horrible luck with birds and pickle worms(squash borer). The birds are taking the tomatoes off of the plant before they even turn red. 9 tomato plants and not one tomato to show for it. The pickle worms completely destroyed 4 very large and healthy cucumber plants. I feel like I have tried everything and nothing is working. I planted all the plants that deter pest all around the garden but they don’t seem to be helping much either. I was really excited because this is the first year we have had very large healthy plants. Everything went down hill as soon as they started to produce. The Okra is doing great and hopefully my pepper, carrots, cabbage, and melons all make it through the pest. Thank you so much!
Ashley @ PapertoThread
Hi Ashley,
I’m sorry your having difficulty in your garden. It can be so frustrating when you’ve worked so hard to start losing crops to pests.
I do not (yet) have personal experience with pickle worms but there are a few things you might try: 1. See if there is any way of using a floating row cover to prevent the moth from laying her eggs. Keep in mind however, that you will also be keeping the bees from pollinating your plants so you may need to get in there and try to pollinate them yourself. 2. Plant early to avoid the worm, and/or contact your county extension office to see if perhaps there is a resistant variety that they can recommend. 3. Since the worms cause damage by eating the fruit perhaps BT might work for you?
As far as birds and tomatoes go you can try knee high pantyhose. Use them to cover the tomato clusters, creating a sort of net around them. This will prevent the birds from sampling some. If that doesn’t work, pick your tomatoes at the “breaker stage” when the fruit just begins to turn from green to red (or whatever color you’re growing). Bring them inside and allow them to finish ripening in a cool, dark, dry area. I realize that vine ripened tomatoes are ideal, but bringing them in early will at least ensure that you will be getting some. Picking them at that stage also helps with other problems like cracking.
Other ways in general to stay ahead of your pests are to plant more crops to compensate for the loss, and if you are able to start transplants, always have something to replace a lost crop that has to be removed.
Hope that helps. 🙂 Good luck with your peppers, okra, carrots, cabbage, and melons!
I am with thousands of grasshoppers. I don’t want to use something that will completely remove insects from my yard cuz I’m hoping to have chickens in a few weeks.
If you can hang in there for those few weeks, your chickens will love them. I had a problem last year with grasshoppers too. Have you tried using row covers? Sometimes that helps.
We had one grasshopper year like that! You may be able to remove many grasshoppers in the early morning, when they are slow: they like to climb up TALL things (the side of a building, trees, tall plants), so they can get the first rays of sun and warm up. If you don’t already have a high place they like, you could rig one up, then flick them off into a bucket partly-filled with water. Leaving buckets of water around throughout the day can catch quite a few as well: just make sure you empty them every few days so you don’t breed mosquitoes.
The chickens will work miracles for you, too!
The Squirrels won’t leave my Tomatoes alone. What can I do to keep them from eating on my fruit?
Lisa I have not had problems with squirrels (we don’t have many trees) but I would treat them the same way you would treat a problem with birds. Try covering your tomatoes with knee high panty hose. Just pull the hose up around the tomatoes and loosely knot them at the stem. Alternatively, you can harvest them before they are ripe and allow them to ripen inside on the counter. Hope that helps.
I am new to gardening and last year was the first time my family had tried growing veggies. I planted some turnips, which I love, and they grew so beautifully, however the leaves ended up being devoured by tiny little green caterpillars. I had no idea what they were or how to get tid of them and thus we ended losing the entire crop. Any idea what they were and how I get rid of them? Any help would be so appreciated, thanks!
Sharon, based on what you are describing, it sounds to me like the cabbage worm. They like to eat cabbage and cabbage related crops and can devour them pretty quickly. If you have a small crop, the best thing you can do is to just pick them off by hand. Keep a close eye on your plants, checking them every day. Look for nibbled leaves and droppings as evidence of the pests. When you find them, you can drop them into a bucket of soapy water, and when they are dead, toss them into your compost bin. Good luck!
Cabbage worms eat my broccoli and collars with reckless abandon… I try capturing them and feeding to my chickens but they seem to multiplying explosively and I only grow broccoli with rare success honestly.
Brian I feel your pain. I have not been able to control them either and cannot grow cabbage with great success. Last year I purchased some neem oil. I think I might give that a try and see if that helps any. Natural/organic gardening can be such a challenge.
I love the idea of using a board for the squash bugs to collect under! Thank you!
We smash their eggs between two smallish, flat-sided rocks: one rock on each side of the leaf. Pretty easy to do, even for small hands.