Show Transcript
0:00In this video, we're going to be talking about how to manage fall pests.
0:04Different seasons have different pest pressures. And so, if you're planning on growing fall crops and into the winter,
0:10there's some things you need to be paying attention to. So, what are the key things to to be prepared for when it comes to fall growing?
0:21Well, I think the biggest challenges at least that we've had with with fall pests is your worms, your cabbage worms
0:28or army worms. Um, and then aphids.
0:34And those are are largely on the brasacas. And again, because you're starting them in the heat of the summer,
0:42you have to really work hard to get them through the heat to the fall. Um, so you
0:50there's also a possibility for cutworm damage if u you know when you're planting your fall crops.
0:59We found with cutworms that if we keep the weeds out um you know they they seem to there's
1:09certain kinds of weeds like chickweed and stuff that the cutworms love.
1:15And so if we can keep the the chickw weed out and and other weeds then we don't have much issue with cutworms.
1:23Interesting.
1:25But as far as the other worms um there are some very simple solutions.
1:32Probably the most wellknown is uh something like dipel. Now, dipel
1:39is a trade name. Um, but the active ingredient is BT or basillusensis.
1:47Um,
1:49that works wonders on on any of your worms on your brasas.
1:55And you know, at least for us in this part of the country,
2:00it's always an issue. And so we just do like a preventative, you know, every week or 10 days
2:08we're spraying. But they they recommend that you don't just spray dip pill
2:15because there is the potential for the worms to to um what do they call it? You
2:22know, to adapt to it to uh uh res build a resistance or something.
2:29Yeah. Yeah. resistance to it. So,
2:32another one that works really well is um entrust or again that's a trade name. The active
2:41ingredient on this is spinosid and I think I think maybe you all have
2:48one a m insect spray. Yep. That has the same active ingredient. So,
2:55it's going to do the same thing. But that works on your worms. Also works on a few other things. Works amazingly well
3:04on Colorado potato beetles and um flea beetles. Okay.
3:10So, it works well on those. Um,
3:16one thing you have to remember with with brasacas, if you've grown them at all,
3:22you know that water just beads up and rolls off the leaf.
3:28So, you're spraying and the spray is all just rolling off the plants. So, what
3:35you need is something like this. This is called Therex.
3:41It's worked really well for us. It's a natural wedding agent made out of yucka extract.
3:48And so you mix some of that in your tank when you're spraying and then the dipel or whatever you're spraying sticks to the leaves much better.
3:59Okay? So that's an important thing to remember.
4:04When it comes to aphids, aphids can be a big issue in the fall. And um
4:14again, Elliot Coleman shared a couple tips with me that have worked really well. Well, he he
4:22said aphids, the the cause for aphids is either water stress, which is usually in the fall it would be not enough water,
4:34um so the plants are wilting, whatever.
4:37And the the second reason for aphids is too much nitrogen.
4:44So if you can watch those two things and and I think the big one in the fall is the the water stress because again
4:52you're growing a cool weather crop in the heat of the summer when you're starting out. So keep them well hydrated.
5:01Yeah. And um then if you do notice aphids and and the way you'll notice it
5:09if you're scouting regularly, you'll see the leaves are are getting deformed.
5:16And if you look under those leaves,
5:18you'll see many times they're covered with aphids.
5:24The challenge is because they're under the leaves, it's very hard to get the spray on them. We use something called impede,
5:35which is just a insecticidal soap. It's a commercially available insecticidal
5:42soap. There's other varieties. I'm sure you probably sell one. Um,
5:49but basically they're designed to suffocate the aphids by coating them with this soapy mixture.
5:58And if you're not getting where the aphids are, you're not going to suffocate them. And so it's it's a
6:06challenge to to get rid of the the aphids once you get them. So, you want
6:13to do your best to keep from getting them.
6:18And then if you do get them, you're going to have the work of actually trying to spray under all the leaves.
6:25Yeah. Yeah. That's where you're I know you used to use like a backpack like blower sprayer. There's kind of a
6:33difference between just a regular sprayer and one that's actually blowing a lot of velocity of air. Is that where
6:40you use the the air blower to kind of turn the leaves and exact get from all directions?
6:46You know, I would say for starters, you want to at least have a pump up backpack sprayer. Yeah.
6:53You know, anything you're having to pump by hand and carry. That's just not efficient enough for a market garden.
7:01But you can start with a hand pump, backpacker,
7:04backpack sprayer. M um then the next step up would be a batterypowered backpack sprayer. But then I think the
7:13ultimate solution is what they call a mist blower. We have a steel that we love and the beauty of it is it just
7:22moves the leaves all around and helps you to get under there and get the coating on the insects. There's a lot of information we've shared in this video,
7:32but a lot of great snippets of information to help uh deal with manage some of those fall pests that can be a
7:40nuisance. So, I hope that some of this information has been helpful to you and until next time, happy growing.
7:47[Music]
The biggest fall pest challenges for market farmers are cabbage worms and army worms on brassicas, followed by aphids. For worms, a preventative spray rotation of BT (Dipel) and spinosad (Entrust or Monterey Garden Insect Spray) every 7–10 days is highly effective — just add a natural wetting agent like Therm X so the spray actually sticks to waxy brassica leaves. For aphids, prevention is key: keep plants well-watered and avoid excess nitrogen, because once aphids establish under the leaves, they're very difficult to reach with sprays.
Different seasons bring different pest pressures, and fall is no exception. If you're planting fall crops now — especially brassicas — there are specific pests you need to be ready for, because you're starting cool-weather crops in the heat of summer, and that transition period is when they're most vulnerable.
My dad, John Dysinger, has been navigating fall pest pressure at Bountiful Blessings Farm for 27 years. In a recent video, we talked through the pests he deals with most in fall, the organic sprays that have proven effective, and the practical tips that make the difference between a spray program that works and one that doesn't.
What Are the Most Common Fall Pests on a Market Farm?
For market farmers — especially those growing brassicas — the three biggest fall pest problems are cabbage worms, army worms, and aphids.
Cabbage worms and army worms are the primary threat to any fall brassica crop. Because you're starting these plants in the heat of summer and growing them through into fall, worm pressure is nearly constant during the establishment period. At Bountiful Blessings Farm, it's always an issue in our part of the country.
Aphids are the other major fall challenge, again largely on brassicas. They're sneaky — by the time you notice the damage, they've often established large colonies on the undersides of leaves where they're extremely hard to reach with sprays.
Cutworms are also worth watching for when transplanting fall crops. My dad has found that cutworm damage is closely linked to weed pressure — certain weeds like chickweed attract cutworms, and keeping beds clean significantly reduces the problem. If you're staying on top of your weeds, cutworms are much less of an issue.
How Do You Control Cabbage Worms and Army Worms Organically?
For worms on brassicas, my dad uses a simple, preventative spray rotation that has been reliable for years.
BT (Bacillus thuringiensis)
The most well-known organic worm control is BT, sold under the trade name Dipel (among others). The active ingredient is Bacillus thuringiensis, a naturally occurring soil bacterium that's lethal to caterpillars but harmless to beneficial insects, animals, and people.
At Bountiful Blessings Farm, my dad sprays BT preventatively — every 7 to 10 days during the fall growing period. He doesn't wait until he sees damage. By the time worms are visibly eating your brassicas, they've already set you back.
Spinosad (Entrust / Monterey Garden Insect Spray)
The key recommendation is to not rely on BT alone. There's potential for worms to build resistance to any single product over time, so rotating with a second active ingredient is important.
Spinosad — sold commercially as Entrust for farm use, or as Monterey Garden Insect Spray for smaller-scale applications — is an excellent rotation partner. It's also derived from a naturally occurring soil bacterium and is OMRI-listed for organic production.
Spinosad handles worms effectively, and it has the added benefit of working on a few other common pests including Colorado potato beetles and flea beetles. Alternating BT and spinosad sprays on your 7-to-10-day schedule gives you strong worm control while reducing the risk of resistance.
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The Wetting Agent Trick You Need to Know
Here's a practical detail that makes a real difference — and one that's easy to overlook.
If you've grown brassicas at all, you know that water beads up and rolls right off the waxy leaves. That means your carefully mixed spray is doing the same thing — rolling off the plants before it can work.
The solution is a natural wetting agent. My dad uses Therm X, which is made from yucca extract. You add it to your spray tank and it helps the BT or spinosad actually stick to the leaves instead of running off. It's a small addition that dramatically improves spray effectiveness on any waxy-leaved crop.
How Do You Prevent and Control Aphids in Fall?
Aphids are a different kind of challenge. Unlike worms, which you can hit with a preventative spray rotation, aphids are much harder to treat once they're established — which makes prevention the priority.
Prevention: Water and Nitrogen
My dad credits Eliot Coleman with two insights about aphids that have proven true in his own experience:
Water stress causes aphids. Plants that aren't getting enough water become vulnerable. In the fall, this is the bigger risk because you're growing cool-weather crops during the heat of late summer. Keeping your fall transplants well-hydrated during that establishment period is critical.
Too much nitrogen causes aphids. Excess nitrogen produces lush, soft growth that aphids love. If you're seeing recurring aphid problems, take a look at your fertility program — you may be overdoing the nitrogen.
Get those two factors right, and you'll dramatically reduce your aphid pressure before it starts.
Treatment: Insecticidal Soap and the Right Equipment
When you do find aphids — and you'll spot them by looking for deformed leaves, then checking the undersides where colonies cluster — the standard organic treatment is insecticidal soap. My dad uses a product called Impede, but there are several commercially available insecticidal soaps that work on the same principle: coating the aphids with a soapy mixture that suffocates them.
The challenge is getting the spray where the aphids actually are. They live on the undersides of leaves, and a standard spray pattern just hits the tops. If you're not reaching the aphids, you're not solving the problem.
This is where equipment matters:
At minimum, use a pump-up backpack sprayer. Anything you're pumping by hand and carrying in front of you just isn't efficient enough for a market garden.
A step up is a battery-powered backpack sprayer, which saves you the pumping effort and lets you cover more ground.
The best option is a mist blower (my dad uses a Stihl). The high-velocity air from a mist blower physically moves the leaves around while spraying, helping you get coverage on the undersides where the aphids are hiding. For aphid control specifically, this makes a significant difference.
How Do You Scout for Fall Pests?
Regular scouting is your early warning system. My dad doesn't wait for visible plant damage to act — by the time holes appear in brassica leaves or you notice stunted growth from aphids, you've already lost ground.
For worms, the preventative spray schedule handles most of the problem. But for aphids, get in the habit of flipping leaves over when you walk through your brassica beds. If you catch a small colony early, you can spot-treat before it spreads. Once aphids are established across a planting, you're in for a much bigger fight.
For cutworms, watch your transplants closely in the first few days after planting. If you're finding seedlings cut off at the base, cutworms are the likely culprit — and cleaning up weed pressure, especially chickweed, in and around your beds is the most effective long-term control.
The Takeaway
Fall pest management comes down to a simple framework: spray preventatively for worms (rotating BT and spinosad on a 7-to-10-day schedule with a wetting agent), prevent aphids through proper watering and balanced fertility, and scout regularly so you catch problems before they become disasters.
Don't skip the wetting agent on brassicas — it's a small detail that makes your spray program actually work. And if aphids are a recurring issue, invest in a mist blower that can reach the undersides of leaves where the colonies live.
Fall growing is one of the best opportunities on a market farm. Don't let pests take it from you.
Frequently Asked Questions
Cabbage worms, army worms, and aphids are the three biggest fall pest challenges for brassica growers. Worms cause direct feeding damage to leaves, while aphids colonize the undersides of leaves and cause deformation and stunted growth. Cutworms can also damage newly transplanted fall seedlings.
BT (Bacillus thuringiensis) is a naturally occurring soil bacterium that's lethal to caterpillars when ingested but harmless to beneficial insects, animals, and humans. Sold under trade names like Dipel, it's one of the most widely used organic pest controls. Apply preventatively every 7–10 days during fall worm season rather than waiting for visible damage.
Worms can build resistance to any single pesticide over time. Alternating BT with a spinosad-based product like Entrust or Monterey Garden Insect Spray reduces resistance risk while providing effective control. Spinosad also controls additional pests like Colorado potato beetles and flea beetles.
Brassica leaves have a waxy coating that causes water and sprays to bead up and roll off. Adding a natural wetting agent like Therm X (made from yucca extract) to your spray tank solves this problem by helping the spray adhere to the leaf surface. Without a wetting agent, much of your spray application is wasted.
According to Eliot Coleman — and confirmed by decades of experience at Bountiful Blessings Farm — the two primary causes of aphid infestations are water stress and excess nitrogen. Keeping fall transplants well-hydrated during the hot late-summer establishment period and avoiding over-fertilization with nitrogen are the best preventative measures.
A mist blower is the most effective option because the high-velocity air moves leaves around, allowing spray to reach the undersides where aphids hide. A battery-powered backpack sprayer is a good mid-range option. At minimum, use a pump-up backpack sprayer — hand-pump carry sprayers aren't efficient enough for market garden scale.
Keep beds and surrounding areas free of weeds, especially chickweed, which attracts cutworms. At Bountiful Blessings Farm, cutworm problems are minimal when weed pressure is under control. Monitor transplants closely in the first few days after planting and look for seedlings cut off at the soil line.
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