Planting Cucumbers with Surround WP

 

 

Growing cucumbers is an almost impossible task lately because of the cucumber beetle problem here. The beetle harbors a bacterial wilt disease in its gut and infects the cucumber vines when it feeds on them. The actual damage done by the beetles is minimal, but their bite is the kiss of death to the vines if they are carrying bacterial wilt (Erwinia tracheiphila). Within a few days the vine starts drooping and eventually dies as the bacterial infection clogs up its vascular system. There is no cure except prevention, and that is difficult. The beetles are tiny and elusive, and they like to hang out inside of the cucumber flowers which makes them difficult to locate. I have not had success controlling them.

 

This year I am going to try something new and use a kaolin clay product, Surround WP. Surround is a finely ground white clay that is used to coat the leaves and stem of the plants you want to protect. It is not a pesticide but a deterrent to insect activity. It comes in a 25-pound bag and is mixed with water to form a slurry, which is either sprayed or used as a dip. Since I started my cucumbers inside in peat strips, I chose to dip the plants in a bucket of Surround for first application. Later on I will have to spray the plants to reapply it after a rain.

 

 

 

I used a small one gallon bucket to mix the slurry, adding water to the powder and stirring to get it wetted. I tried a stick at first but found my fingers were more effective. You want the slurry thin enough that it drips but does not run off the leaves.

 

 

When ready to plant, I took a peat strip, broke off the top edges so they will not stick out of the soil, and swirled the plant in the clay slurry.

 

 

Once the plant is reasonably coated, it is ready to put in the ground, looking like a white ghost. I wondered if the clay has a negative effect on the plant, but it apparently does not and has some advantages. The clay breathes and sunlight can get through so photosynthesis is not affected. At the same time, the clay prevents sunburn of new plants and reduces transplant shock.

 

 

Here is a row of newly planted Homemade Pickles, a pickling cucumber, looking quite ghostly.

 

 

The most difficult to plant were the Monika cukes above, a pickler from Poland. The plants were very compact so it was difficult to plant them without soil getting on and sticking to the wet clay.

 

Time will tell if this type of treatment works. UMass seems to think it does. It is important to start it at plant out because cucumbers are most susceptible when they are young (less than 5 sets of true leaves). Surround is widely used by commercial growers and both Johnnys and High Mowing Seeds use it in their fields. It is widely used in orchards and vineyards. And it is also useful for other plants and pests, such as flea beetles on eggplant, thrips on onions and squash vine borers and squash bugs, so I may apply it elsewhere in the garden, once I get a sprayer than can handle a wettable powder.

Things I May Try in 2015

 

I have been thinking of some things I may want to do differently in the garden in 2015. I use the word “may” because I reserve the right to bail out on any or all of this. This is not my New Year’s resolution list.

 

Purchase Onion Plants

The last three years I have been growing storage onions  in my garden. I use seedlings because the results are much better than sets. After all, alliums are biennial and there is a risk with sets that the plants will bolt, plus you are severely limited in your choice of onion varieties. Starting onions from seeds is really not hard. They take a while to germinate and here you have to start them in February, but they do well in cool conditions (the definition of conditions in my house in February with $4 heating oil). But I did manage to do a bad job last year. Trying to plant black seed in black potting mix is difficult, so I just sprinkled the whole packet in a 4” pot. The seedlings were crowded and too difficult to thin, resulting in weak transplants, many of which died from transplant shock.

 

This year, I am going to try using purchased onion transplants, at least for the yellow and red storage onions. I will still have to start seed for the shallots and specialty onions This is an expensive  proposition, about twice as expensive as purchasing seeds and starting you own. What I am hoping to achieve is a much higher (more and bigger bulbs) and more reliable yield from the same garden space because I will be planting robust and healthy transplants grown by professionals. A lot of seed vendors sell onion plants and most seem to be grown and shipped  by suppliers in Texas (Dixondale Farms being one of the most prominent). And most of those seed vendors get about $15-16 for a bunch of 50-70 plants. Fortunately, Pinetree Seeds in Maine sells two bunches for $15.49 and you can mix and match. So, one bunch of Copra and one of Red Zeppelin for me. One of the many reasons I really like Pinetree.

 

Total War on Cucumber (and Flea) Beetles

OK, I have had it. This year, once again, my cucumbers were decimated by bacterial wilt spread by cucumber beetles. These pests feed on the leaves of cucumbers and their larvae feed on the roots. The leaf damage is not that bad, and cucumber plants can usually recover. What is worse is the beetles carry bacterial wilt disease in their guts and spread it to the plants. Once infected, the plant wilts and dies in just a couple of days. The little buggers are small and fast, and they like to hang out inside the flowers, so they are difficult to hand pick.

 

So in 2015 I am going to try using Surround for the cucumbers and eggplant, spread DT on the soil around the plants, and spray weekly with an organic spray like pyrethrin or Spinosad (I usually alternate these). Surround is an interesting material and it will be a challenge to use it. Surround is a finely ground kaolin clay produced in a magnetic centrifuge in Georgia by one company. It’s a patented process using fancy and expensive equipment, so the product is fairly pricey. Both Johnny’s and Fedco carry it, but Fedco is about $5 cheaper for a 25 pound bag. Shipping is another matter so I may try to find a local source.

 

The way Surround is used is a slurry is made with water and the plants are either dipped in it before transplanting, or you use a sprayer to apply it. I will probably try dipping the transplants and then use a sprayer to cover new foliage and touch up spots that are washed off. The film left by the clay apparently doesn’t affect the plant and transmits light. There are various theories on how it works, such as the beetles don’t see the plants, they don’t like the feel of it, they spend their time cleaning their little feet rather than feeding, but it apparently does work and is used by commercial growers. An option is to mix a pyrethrin with the clay slurry when applying, but there is no evidence that improves effectiveness.

 

Row cover for Brassicas and Eggplant

Obviously, row cover for brassicas, eggplant and squash makes a lot of sense, given  the plethora of pests they face. I have used squares of the stuff in my square foot garden, supported by arches of plastic tubing. Last year I had access to one of the unused plots in our community garden and reverted back to traditional, in-ground row gardening. I may have that privilege again and want to try planting brassicas and eggplant in-ground, so a row covering makes sense.

 

I ran across an article on the Grow Abundant Gardens blog with a nifty way to implement a floating row cover. Turns out Johnny’s sells a 10 foot wide Agribon AG-19 in rolls. This is wide enough that if you use, say, 10 foot sections of 1/2 inch plastic conduit as supports, you can create a tunnel high enough to grow broccoli, Brussels sprouts, eggplant and summer bush squash under it. The row cover helps with cool Spring weather for the eggplant and squash and repels the nasties for anything you plant under it. I’m going to give this a try.

 

Grow Peas on a Trellis

I am getting tired of the results achieved from my patented technique for growing snow and snap peas in a block. I have tried to select varieties that are short vined, such as Oregon Sugar Pod II. I plant them in a block surrounded by a low fence and hope they support each other as they grow. Good theory, but in practice they usually grow taller than the catalog claims and flop over. I get a big mess and it is hard to find the peas to harvest them

 

So next year I am going to try growing them on a trellis. In fact, they are going to get the 8 foot trellis I grew the Musica beans on. I think I will select a tall variety like Green Beauty from Fedco, which is supposed to grow to 8 foot and produce heavily. Instead of an occasional handful for a stir fry, I envision bags and bags of snow peas in the freezer next summer.

 

Mineralization

This is a topic somewhat new to me and big enough that I may save it for another post. Obviously, if we are eating our own garden produce, we want food that is “nutrient dense” and healthful. That’s why we garden. A key to producing nutrient dense food is having garden soil that has the right mix of macro and micro nutrients. According to Mel Bartholomew, all you need is a trowel full of “perfect” compost per square to produce healthful food. Of course, no one can define what “perfect” compost is and even Mel himself has admitted that sometimes supplements help. For example, he acknowledges that broccoli and beets are boron dependent and supplying a boron boost can increase productivity and eliminate hollow stems. I will write more later but mineralization will get increased attention from me in 2015.

 

Tomato choices

As I have said, I had access to an extra plot in the community garden and planted a double row of tomatoes. I am more careful what I plant in my square foot garden because of its limited space. So I took advantage of the additional space and planted some heirlooms. I planted four Brandywine, four Pineapple, and a Cherokee Purple, all heirlooms. At first, results were great and I got a heavy set of fruit, but they took their good old time ripening. Unfortunately, by late summer, most of the fruit cracked and anthracnose rot infected the cracks before the fruits ripened. I lost a large amount of fruit because of that. So next year I will put a bigger emphasis on selecting full size tomatoes that are more crack resistant. It doesn’t matter what the flavor is if the fruit rots before you can eat it.

 

 

 

Flea Beetle Management

A few years ago, the flea beetles were a curiosity in the community garden. I noticed a few shot holes in my eggplant. which were waist high at the time and not really bothered by the beetles. But every year since then the beetles have increased their numbers and their appetites. It has gotten so bad that I cannot grow eggplant at all and the quality of many of my Cole crops is affected. I’m pissed off and I declared war on the flea beetles this year, which is kind of ridiculous considering how tiny they are. Flea beetles are nasty and really hard to control, so I only used the term management in my title, but here is what I am trying.

 

 

First, you have to understand the enemy. Flea beetles winter over as adults in the soil, usually in wooded areas near the field or your garden. They emerge in spring as soon as temperatures get to 40F and go looking for breakfast. There are as many as 3-4 generations a year and adults can live up to 2 months, so that's a lot of munching. In my area, flea beetles are present up to frost and beyond.  The larvae live in the soil and feed on the roots of the plant before emerging as adults. Usually the damage to roots is minimal except in the case of the potato flea beetle, where the larva can significantly damage the crop.

 

There are many kinds of flea beetles and they usually feed on one type of plant. In my garden the two biggest pests are probably (I'm not an entomologist) the crucifer flea beetle (Phyllotreta crucifera) that feeds on brassicas, and the eggplant flea beetle (Epitrix fuscula) that feeds on solanaceous plants (tomatoes, peppers, but mostly eggplant). Whatever type of flea beetle, the adults feed on the leaves of the plant, chewing tiny holes all over the leaf (an effect called shot holing, looking like the leaf has been hit with shotgun pellets)

 

Row cover works if you put it on early enough and seal the edges very well. That's assuming the beetles didn't overwinter in the soil under the covers. I tried covering my eggplants last year (in brand new Mel’s Mix so no eggs) but they still got in. And they eventually killed all my eggplants, even the ones with 4-5 leaves, so much for that theory.

 

You can try physically removing the beetles. Last year, each visit to the garden started with an examination of the eggplants and brassicas to pick and kill flea beetles. They are tiny, hard-bodied beetles and hard to catch and squish. I find it more effective to use my thumb to trap them and then, with my fingers under the leaf, roll the beetle to the edge of the leaf. If the beetle hasn’t disintegrated by then,you can roll them between your thumb and finger until they do. A trick I haven't tried yet is to use a hand-held vacuum (dustbuster) to vacuum up the beetles. This sounds tedious but my theory is every beetle you destroy is one less beetle laying eggs and multiplying.

 

Trap crops properly done probably work for farmers who, say, surround their field of broccoli with a 4-foot band of mustard. The beetles flying out from the woods land on the mustard, and the farmer then heavily sprays the trap crop with insecticide. I don't believe planting some radishes next to your broccoli is going to lure the beetles away. In fact I know it won't, because the radishes I have near the broccoli are ones I actually want to eat, and both the radishes and the broccoli are being chewed up. And I guarantee you planting radishes near your eggplant is not going to lure eggplant beetles away. The beetles you see on the radishes are crucifer beetles, not eggplant beetles, and are now ready to move on to the main course, your brassicas. And obviously, garden areas should be kept free of weeds where beetles can shelter and feed, particularly weeds in the mustard and solanaceous families (and I include volunteers in the category of weeds).

 

You can try dusting the leaves with DE (diatomaceous earth), which either irritates them or slashes their little bodies. I haven't found this very effective but you can give it a try. I have also used a garlic chili spray, which seems to repel (but not kill) them for about a day. I make the spray by putting 2-3 cloves of garlic and a chili in a food processor with a cup of water. Puree then let steep for a day. Strain into a quart spray bottle, add a few drops of dish soap, and dilute with water to a quart.

 

If you are willing to use organic sprays, pyrethrin sprays are moderately effective but short lived. They degrade quickly with exposure to sunlight. Look for a spray that has an OMRI label and is not mixed with piperonyl butoxide, which makes it unsuitable for organic gardens. Also avoid spraying it when pollinators are active in the area.

 

A new and better substance is spinosad, an organic insecticide produced by fermentation with a common soil bacteria. Spinosad is a stomach/nerve poison and has to be ingested, so it is safe for beneficial insects, earthworms, and pollinators as long as it dries before contact. It can be used up to day of harvest. Flea beetles were recently added to the insects it will control and in tests it is more effective than pyrethrin and persists longer. In addition, it will also control cabbage loopers and caterpillars, so you get a two-fer when you spray your brassicas. It also controls leaf miners and will penetrate and kill the maggots inside the leaf. I sprayed my brassicas and observation the next day showed only a few flea beetles present. I also bought some pyrethrin spray and plan to try alternating spinosad and pyrethrin through the season so resistance does not build up.

 

Another product used by commercial growers is Surround WP, a kaolin clay compound that coats the leaves and acts as a repellant and protectant. When mixed with water, transplants can be dipped in a bucket of it before setting them in the ground. Rain will eventually wash it off so you have to spray to reapply it. And it will discolor fruit like eggplant so it can’t be used after fruit has set. For flea beetles it was not as effective as spinosad but works well on other pests.

 

Hopefully, you don’t even know what a flea beetle is. But if you have them, good luck in managing them. If you have other techniques that work, I would be interested in what you have done.

 

Squash Vine Borers

Squash vine borers (SVB) are larvae of the SVB moth that bore into the stems of cucurbits (squash, cucumbers, melons) and work their way up the stem. You can tell you have borers when your plant suddenly wilts. Check the stem about an inch and a half up from the ground and you will see a small hole with sawdust around it where the borer entered.

Once the borer is in the squash, the plant is at great risk. If you catch it early enough, you can slit the stem with a razor knife from the entrance hole up to where the borer is and destroy the borer with the knife blade or a wire. Then bury the slit stem under soil to keep it covered. This may or not be successful, but if you do nothing, the plant will die. If the plant can’t be saved, pull it and destroy it. You can replant squash in early July after the SVB threat is over.

The best method is to prevent the SVB from laying eggs near your squash, or provide a physical or biological barrier. If you can cover your plants with floating row cover, that keeps the moths from laying eggs near or on the plant. It also wards off squash bugs. But the cover has to be removed when the plant starts flowering so pollinators can get to the flowers.Last year I kept my squash covered, even hand pollinating them for a while.. This year with varieties like Costata Romanesco, which grow very large, I am not sure if I will be able to keep them covered for long enough, so I am interested in other possible prevention techniques.

The SVB moth does not look like a moth but more like a wasp or bug. It emerges from a cocoon in the soil the end of June or beginning of July (but remember we are way ahead of average on degree days because of the mild winter and spring). These moths fly during the day and are very good fliers, more like a wasp. They stand out because of their coloring so keep a lookout for them.



The moth lays single brown eggs on the stems of the cucurbit. When they hatch, the larvae tunnels into the vine about an inch or inch and a half off the ground. The borer itself is a big, fat, ugly thing, shown here in this cross-section. These pictures are courtesy of the University of Minnesota Extension (see http://www.extension.umn.edu/distribution/horticulture/M1209.html for their advice on SVB management).



Here is an interesting video that suggests using cardboard tubes to prevent the borers from physically reaching the stem and boring into the plant.



Other suggestions are to wrap aluminum foil around the stems at the soil level and several inches up. Another, more elaborate technique is to inject the squash stems with a Bt (Bacillus thuringiensis) solution, inoculating the insides of the stems with Bt, which will kill the borers when they try to enter the stem. Does anyone have experience with these prevention methods? I am curious to know if they really work.

This was originally posted on the Bolton Community Garden Blog and is re-posted here because I thought the information might be useful.

Garden Update 20 June 2012

It has been two weeks since my heavy planting effort on May 26-27, the Memorial Day weekend. All of the transplants survived and are actually thriving, despite the cool, cloudy, rainy weather. I did not have to worry about the keeping the seeded beds moist. All the rain took care of that for me. I did worry about the bean seeds, which prefer a warm, fairly dry soil of at least 60° F (16° C). That planting weekend was warm and sunny but early this week we had overnight lows in the forties. Nonetheless, everything has now germinated and is doing well.

Speaking of beans, the pole bean Fortex was one of the first to come up. They are going to be trained up a trellis on the left. The rest of the box has my kale and collards transplants along with a few remaining kale plants from last year. I have been planning to remove the old plants, so I shear them of leaves and come back to find them looking like this. I’m getting buried in kale. I also need to get them doused with bT and covered with row cover to ward off the cabbage moths floating around the garden now.

UMass Extension Vegetable Program

The Agricultural Extension Program at UMass Amherst has a Vegetable Program for growers of vegetables. While the Program is aimed at commercial growers of vegetables and herbs in Massachusetts, their web site has lots of useful information of value to home gardeners throughout New England. For example, they have a page on the halo bean blight that hit my pole beans after TS Irene.

In addition, they have an email newsletter called Vegetable Notes that is well worth subscribing to. It provides an update on disease and insect prevalence in New England and suggests what measures can be taken to protect your garden. The advice is oriented toward commercial growers and is not necessarily suited for organic growers, but is still useful to us home gardeners.

The September 8 newsletter provided a lot of useful information on how to deal with the effects of storms Irene and Lee, which included flooding followed by outbreaks of disease and insect infestations. Certainly in our community garden, we have seen many of the problems described in the newsletter. Fortunately for us, flood water in the garden was only a few inches deep and was clear and not full of mud, but we still got the mildew and rot that followed.