Good news – great hoeing weather! Bad news – more nematodes in the hoophouse

Fall broccoli last year. Credit Ezra Freeman
Fall broccoli last year.
Credit Ezra Freeman

Last week I wrote about transplanting cabbage and sowing kale. We were having “great transplanting weather”, that is, it rained a lot! We filled all the gaps in all 12 rows of broccoli and cabbage in a single hour with four people. There weren’t many gaps, happily. That’s about 1400 broccoli plants and 700 cabbages, our usual amount to feed a hundred people.

This week in the garden, it’s about three weeks since we started the transplanting, so the first rows are ready to be uncovered and hoed. Happily, we now have great hoeing weather! No rain in sight for a week. Central Virginia weather is very variable, and our particular spot is drier than the surrounding area, so if the forecast says 30% chance of rain or less, we are very unlikely to get any. There’s currently a forecast with a 50% chance of rain in 6 days (Monday night). If we can get all the hoeing done, and till or wheelhoe between the rows, then I can broadcast a clover mix and welcome some rain! We like the wheel hoe if the weeds are not too big and not too grassy. The first few rows were quite grassy, so we used our BCS 732 tiller from Earth Tools.

We cultivate around the brassica plants, then broadcast a mix of clovers: 1 oz crimson clover, 1 oz large white Ladino clover and 2 oz common red clover (medium, multi-cut) per 100 square feet. Then if it doesn’t rain, we water like crazy for a few days, which is all it takes to get the clover germinated. We have drip tape for the brassicas, but we need overhead sprinklers for the clover mix. The crimson clover is the fastest growing in the fall, and the others gradually take over in the spring and summer of the next year. We like watching the progression from crimson clover to red to white as each type comes into its strength.

This method of undersowing clovers in fall brassicas works well for us. It provides cover for the soil, legumes which provide nitrogen for the crop. The clovers survive the winter, and in the spring, we mow off the dead broccoli stems and let the clover grow. If all goes well, we keep the clover mix for a whole year (our Green Fallow Year), feeding the soil and eliminating weed seeds. We mow it to prevent the crimson clover seeding (which could be a nuisance) and when ever any weeds seem to be gaining. Here’s a couple of pictures from a previous year. (That’s our Dairy Barn by the side of the driveway, and our Hay Barn in the distance.)

Broccoli in fall after the clovers grow. Twin Oaks Community
Broccoli in the late fall after the clovers grow.
Twin Oaks Community
In March, the old broccoli trunks are surrounded by a sea of green clover. Photo by Kathryn Simmons
In March, the old broccoli trunks are surrounded by a sea of green clover.
Photo by Kathryn Simmons

I’ve written up this method as part of an article for Growing for Market magazine, for the September issue.


And now our bad news – more nematodes in the hoophouse. When we pulled up our early tomatoes, the roots of four of them in one bed were gnarly with lumps. It’s the return of the Root Knot Nematodes.

Credit University of Maryland
Credit University of Maryland

In the early spring of 2011 we found spinach with lumpy roots. We sent some plants with  soil attached, to the Plant Diseases Clinic and got the diagnosis of Peanut Root-Knot Nematodes. We put that half a bed into a series of cover crops, (wheat and white lupins in the winter, French marigolds and sesame in the spring) and solarized it each summer, for two years. In the summer of 2013, we grew Mississippi Silver cowpeas there (resistant to RKN). This past winter we grew lettuce in the that affected half-bed. We benefited – no sclerotinia drop in that lettuce crop, thanks to the summer solarization!

Meanwhile in the early summer of 2013, we found some beans with lumpy roots in the other half of the bed, so we started the same treatment there. Next summer (2015) we could grow the cowpeas there.

Our first (baggy) attempt at solarization in the hoophouse. Credit Kathryn Simmons
Our first (baggy) attempt at solarization in the hoophouse.
Credit Kathryn Simmons

But now the next bed over has nematodes. Having a half-bed out of production is manageable, but one and a half is more of a blow. We are considering whether we need to be as cautious, or whether we should accept that some level of nematode infestation is likely in hoophouses in the south. We are looking at various scenarios. This research has consumed all my available time this week. Information about nematodes is sometimes too general to be useful, as there are many kinds other than root-knot ones. Plus, what’s true for Peanut RKN is not necessarily true for Southern RKN or Northern RKN. Grr!

I’ve assembled a long list of tomato varieties resistant to some kind of RKN, although I don’t yet know which of them are resistant to Peanut Root-Knot Nematode. Many, many food crops are susceptible. Most of the resistant crops are ones we don’t want to grow in the hoophouse: Jerusalem artichokes, globe artichokes, asparagus, horseradish, rhubarb, maybe sweet corn (opinions vary on its resistance/susceptibility).

Maybe we could grow West Indian gherkins one summer. We’d get soooo many pickles! It’s a very productive crop for us. One idea was to build a second hoophouse and use the old one for (resistant) strawberries for two years! We’re not really at the place to do that, though, financially or time-wise.

Currently I’m studying a list of biocontrols to see what’s available and affordable. Life goes on. Hopefully we can decide at our crew meeting on Thursday, because we can’t start to implement our fall planting schedule in the hoophouse until we decide about the nematodes.

Fresh air hoophouse, seedling winter crops

Well, it’s the weekend, and I said I’d let you know how it’s gone with our hoophouse renovations. the answer is – we haven’t got the plastic on yet, check in again next weekend! We have got the west wall braced with diagonal tubing. We have got the old blower replaced with a new one.

For the geeks, here’s the air intake for our hoophouse blower.
Photo credit: Kathryn Simmons

We have got screws in some of the connectors holding the purlins and bows together. We have got all the south-side baseboard off and the rotten bit from the north side. We have got new baseboards (Eastern Red Cedar) cut to length. Unfortunately they ended up a bit thicker than the old ones, not sure why, so the bolts we bought are too short. More hasty shopping! We have got all the old duct tape off the bolt heads and metal connectors and replaced it with shiny new duct tape. It’s to protect the plastic sheeting when we pull it over. We’re planning a little crew party for when it’s done.

Brite Lites chard in our hoophouse.
Photo credit Pam Dawling

Meanwhile we are harvesting our seed crops of Mississippi Silver cowpeas and Envy edamame from in there, and we are prepping beds for the winter crops. We have sown seedlings in one of the outdoor raised beds, to plant out in the hoophouse starting in a few days. Our first round of sowings, on 9/15, included some Brite Lites chard and ten varieties of lettuce, 75cm of each.

Our winter hoophouse lettuce has challenges with a disease we call Solstice Slime (as it arrives around the winter solstice), although it’s generally called Sclerotinia Drop. The best slime resistant ones for us are  Merlot, Oscarde, Tango, Winter Marvel, Hyper Red Wave. Next best: Outredgeous, Winter Wonderland, Salade de Russie, Red Salad Bowl, North Pole. Less good: Roman Emperor, Rouge d’Hiver, Devil’s Tongue, Salad Bowl.

We also sowed some Asian greens, enough to transplant 50-60 each of Pak Choy, Blues Chinese Cabbage, Yukina Savoy and Tokyo Bekana.

Tokyo Bekana
Photo credit Southern Exposure Seed Exchange

On 9/23 we sowed a short row of Pumba onions in the hoophouse as an experimant – they are a more southern variety. Our hope is to get some earlier onions this way. We tried this last year, but many of them bolted, so I’m starting later this time around.

Mizuna
Photo credit Southern Exposure Seed Exchange

Our second outdoor sowing for the hoophouse was 9/24 and we sowed more lettuce:  Hyper Red Wave, Merlot, Red Salad Bowl, Outredgeous, Revolution, Salad Bowl, Tango, Winter Wonderland.  Our notes sternly say “Not Oscarde” for this sowing, although it does fine from the first sowing. Details! We are trying Panisse and Red Tinged Winter this year.

Red Russian Kale
Photo credit Southern Exposure Seed Exchange

We also sowed Red Russian Kale (132 plants) White Russian Kale (117plants) Kale Galega de Folhas Lisas (15 plants) Senposai (140 plants) Yukina Savoy #2 (50 plants) and Mizuna #1 (40 plants). We are growing some green mizuna and some purple, also some Ruby Streaks, which is like mizuna but more mustardy.