Multileaf lettuces – Sustainable Market Farming

In early November, during the Carolina Farm Stewardship conference I went on the afternoon bus tour to see 10 high tunnels and how they’re used for season extension, irrigation, disease control, pest protection, and trellising. Red Hawk Farm grows salads and greens year-round in six high tunnels (more under construction!), and sells primarily to local grocery stores and restaurants. Funny Girl Farm grows produce year-round for its popular farmstand and CSA, with four high tunnels and a greenhouse.They were focusing on the sweet potato harvest outdoors when we visited.

Red Hawk Farm hoophouse densely planted with multileaf lettuces.
Photo Pam Dawling

At Red Hawk Farm I was astounded to see this whole hoophouse planted wall-to-wall with multileaf lettuces. No aisles! The farmer Brett Evans plans to harvest with a walk-behind motorized salad harvester machine that makes a 4 ft wide cut. Then he’ll leave the lettuces to regrow. He uses the paperpot transplanter which I mentioned last week. Here are the starts growing in their propagation house.

Lettuce starts in paperpots at Red Hawk Farm.
Photo Pam Dawling

They still had peppers bearing well in one high tunnel

Early November pepper harvest at Red Hawk Farm.
Photo Pam Dawling

Another interesting feature was the opening roof vent, which I had not seen in operation on a hoophouse before.

Opening roof vent on a hoophouse at Red Hawk Farm.
Photo Pam Dawling

And this past week, I went to Potomac Vegetable Farms in northern Virginia for a talk with Future Harvest CASA members, and a tour of the hoophouses used there led by farmer Zach Lester. I was interested in seeing the success he is having with caterpillar tunnels. These are smaller tunnels with a single layer of plastic, held in place by ropes, as you see in the photo below. They can be temporary or short-term, and Zach showed us one which is a “swing house” with two sites side by side, sharing one row of ground posts, and having just one row to move each time. Another way to deal with crop rotations and reduce the chances of pests and diseases!

Caterpillar tunnel at Potomac Vegetable Farms.
Photo Pam Dawling

At the ends, the plastic is gathered up and tied to well-anchored stakes, as you can see here.

How the ends of caterpillar tunnels are gathered and fastened to stakes.
Photo Pam Dawling

Zach got these frames custom made by Nolts. They have taller sidewalls than many models. He is also a firm believer in having a ridgepole in caterpillar tunnels, to reduce the likelihood of collapse with snow or high winds. As you can see here, they had some snow already.

Potomac Vegetable Farms caterpillar tunnel showing rolled up side.
Photo Pam Dawling

At both these farms, I learned the technique of laying landscape fabric along the side walls to reduce weed growth. You can burn holes in the landscape fabric where the ground posts go through, and it will keep the weeds away for a long time. I wish I’d known that technique when we put up our hoophouse. We have to hand weed, and in some places we have wiregrass (Bermuda grass) which has grown under the baseboards and even between the boards where there are joins.

Lastly, I have of course visited our own hoophouse at Twin Oaks, and have written a post for Mother Earth News Organic Gardening on Dealing with Snow on Your Hoophouse. So if it’s snowing where you are, you can click on the link to read about that.

Rouge d'Hiver hardy romaine lettuce. Photo Bridget Aleshire — Rouge d’Hiver hardy romaine lettuce.
Photo **Southern Exposure Seed Exchange**

Here’s my monthly article on lettuce varieties month-by-month. I wrote about Lettuce in November a month ago. Of course, at this dark and chilly time of year, plants don’t grow much and our lettuce story is very similar this month to last. Except that we have so much! We are harvesting our hoophouse lettuce mix as well as leaves from the big lettuces in the unheated greenhouse and the hoophouse.

In the unheated greenhouse, we have Green Forest romaine, Hyper Red Wave leaf lettuce, Red Tinged Winter leaf lettuce, Oscarde red leaf lettuce and North Pole bibb. all are looking well.

In the hoophouse in the first planting we have Green Forest, Hyper Red Rumpled Wave, Oscarde, Panisse, Red Salad Bowl, Revolution, Star Fighter and Tango. In the second planting we have some of the same and some different ones: Green Forest, Hyper Red Rumpled Wave, Merlot, Panisse, Revolution, Red Tinged Winter, Salad Bowl, Star Fighter and Winter Wonderland. We are currently harvesting leaves from all the greenhouse and hoophouse lettuces in turn.

These are all looking well too, apart from a few Salad Bowl that have crashed with Sclerotinia Lettuce Drop, known “affectionately” to us as Solstice Slime. It happens at this time of year, around the Solstice – cold damp soil and the presence of spores of this widespread fungus cause destruction of the crown of the plant, which spreads to the leaves and causes the whole plant to collapse into a slimy beige lettuce pancake.

Sclerotinia Drop of lettuce.
Photo http://ipm.ucanr.edu/PMG/r441100711.html

Here is a link to a helpful publication from eXtension: Disease Management in Organic Lettuce Production

Our approach is to try not to over-water in cold weather, and to carefully remove pancaked plants, just before leaving the hoophouse, throw them down-wind into the pasture, and then wash our hands before returning.

Other winter-hardy lettuce we have grown in other years include Marvel of Four Seasons, New Red Fire, Pirat, and Rouge d’Hiver. There are hardy bibb lettuce too: North Pole, Red Cross, Sylvesta, and Winter Marvel, but we have stopped growing them in the winter hoophouse as they are not so useful for harvesting by the leaf and they are more prone to collecting dampness and getting diseased.

I’m sad about the poor showing of our Multileaf lettuces, due I think to keeping pelleted seed too long. My consolation is that we have three lettuce varieties that have a somewhat similar plant type (lots of small leaves that can be removed, letting more grow): Oscarde, Panisse and Tango.

Oscarde letuce Photo Washiington State U Ag Research — Oscarde lettuce
Photo **Washington State U Ag Research**

Panisse lettuce. Photo Johnnys Seeds — Panisse lettuce.
Photo Johnnys Seeds

Tango lettuce Photo Kathryn Simmons — Tango lettuce
Photo Kathryn Simmons

I’ve been taking more bookings for speaking events and groups touring our gardens here. It’s looking promising for me to be at the Mother Earth News Fairs in Asheville (May 6-7) and Vermont (June 10-11). I’ve added in a visit here from the Tricycle Gardens group from Richmond on March 24 and one from the Louisa Master Gardeners on April 13. I’ll add info to my Events page (see the tab at the top of this page) as I get it.

I’ve got my slideshows and handouts ready for the Virginia Association for Biological Farming Conference which is coming up in just a few weeks, January 10-11.

Tag: Multileaf lettuces

Hoophouses I visited this month

Lettuce in December, events updates