Garden Pests - Cabbage Loopers

Pests in the garden are no fun, but they're part of the garden's life cycle and accept that I'll be dealing with some pest or another in each garden, each year. Yesterday, I had a client with cabbage loopers. His landscaper recommended buying bT, but I'm not a fan of adding any inputs to the garden (whether or not someone certifies them as organic) , in particular bacteria.

Then this morning I got the following email from a rooftop gardener in NYC, so I know cabbage loopers are making the rounds this year:

Hi Amy, I hope this email finds you well. Had a frustrating morning of discovering my bibb lettuce was gnawed away, holes in my sage and my mint halfway eaten though. I saw a few little green caterpillar culprits, so after a little searching it seems like these enemies may be cabbage loopers? 

Any advice on how to best get rid of them? My garden is entirely a rooftop container garden if that helps!  Thanks so much!

And so for anyone dealing with loopers currently, here is an easy solution (and my response to the above email):

How long have you had the rooftop garden? Did you plant anything in this pot before the lettuce? (*) Cabbage loopers typically like members of the brassica family - cabbage, broccoli, sometimes kale. (editorial note: I also found a paper siting looper issues for lettuce production in AZ!) Did you notice white moths/butterflies llying around about a week or two ago?

For Cabbage loopers you have them, so now you'll have to pick them off and squish them. From there, you can cover your pots with Floating Row Cover, which will prevent them from landing on your crops. Not super pretty, to wrap all your plants in spun white cloth, but effective. Keep me posted! amyp

*I asked about what she had in this pot before, because crop rotation will often help prevent pests in the garden. If she ALWAYS uses this pot for cabbages, for instance, that could be the invitation for loopers.

Growing Potatoes in a Bag

Potatoes, diggin upHere is some awesome garden geek information on the science behind how potatoes grow. You should really know this if you're planning on growing potatoes - whether in a bag, a pot or a garden bed. Read on!

Potatoes grow underground and are considered a "tuber" -- a plant that is enlarged to store nutrients and has the ability to make a new plant. Potatoes, yams and even dahlias are considered tubers. So why do you need to know what at tuber is?

Here is some great info for all your science nerds to help shed light on the growth pattern of potatoes. Ultimately, this information is meant to help you -- if you’re going to build a potato-loving system that is highly productive, you've got to think like the plant!

You care about what a tuber is because tubers produce plants from a stolon (a sub-soil, sprout-like, horizontal root). The stolon is formed from the axils of the plant -- the place where the stem and leaves connect. I bet you thought potatoes form and grow off of a piece of cut potato? Well instead, potatoes actually grow between the original seed piece you plant, and the above-ground leaves. They're the stem of the plant, not the root.

Potatoes are a member of the Nightshade family (alongside tomatoes, eggplant, and of course, the deadly nightshade), some of which are toxic plants. Nightshades are prone to soil disease and must be rotated around the garden year after year in order to minimize problems with the soil. For a home gardener working in beds, this means diligent planning or designating an area outside your beds for potatoes. (Good news! If you grow in bags on your patio, you don't have to worry about this!)

Lastly, here's an alternative to using soil to mound your potato plant: you can also layer the stem in straw. That's right — just straw. It acts as a growing medium for the potatoes — a clean, unmessy growing medium. No cleaning off soil when you harvest, as potatoes will grow directly into the straw. Even better, in warm climates (down south, for instance), the straw layers help moderate temperatures and insulate the bag, which is perfect for potatoes that don't do well in the heat.