HOW TO GROW LETTUCE IN THE SUMMER (WITH VIDEO).

Lettuce is a crop that is pretty much desired year-round by customers and farmers alike. And if you live anywhere near a place that gets as hot as Kentucky in the Summer for two or three months straight (in a mild year) then you need a good plan for growing summer lettuce.So whether it’s just for yourself or for your customers I thought in this week’s video I would lay out how we grow summer lettuce on our (fairly) Southern farm. Then, in the Fall we’ll follow up with a winter lettuce video so you can strive to have lettuce year-round. Because honestly, whether it’s with beets in the Fall, grilled asparagus in the Spring, or tomatoes in the Summer, there is no time where salad doesn’t hit the spot, amIright?Anyway, below is my rundown for how to grow summer lettuce in case you need to reference this (and because I almost inevitably forget details when I’m shooting these videos). I also wrote an article for Growing for Market last summer about growing summer lettuce that referenced the three growers I mentioned in the video—Ray Tyler of Rose Creek Farms, Erich Schultz Steadfast Farm, and Elliot Seldner of Fair Share Farm. All of these guys grow great summer greens in fairly extreme environments—TN, AZ, and NC, respectively—so check em out.Selecting seedYour first line of defense against summer heat is going to be the seed you purchase. Lettuce needs to be specifically adapted to the intense heat of summer to really survive well. I recommend some in the video, but you will have to experiment in your own situation, program, soil, and market to find what works best for you. Look for the heat tolerant varieties in your seed catalogs, and try a handful. Also consider trying some Salanova, which is both heat and cold hardy, making it an ideal “lettuce mix” to consistently offer year round to restaurants who will come to appreciate (but also expect) the product that consistency.Seed Propagation vs. Direct SeedingLettuce seed has a quality called “thermal dormancy”. This is when the seed gets too hot or cold it won’t even try to germinate. That temperature is really anything over 80 degrees, which is what the soil can get to in the summer. Preferably temps would float around 65 Fahrenheit. This, for the most part (excluding the example I give in the video) is why you will have to transplant your lettuce into soil mix where you control the temperature to keep it going consistently all summer. Of course, that “you can control the temperature” part is important. Lettuce won’t germinate in a hot greenhouse any more readily than in the field so you will have to find a cool place to germinate the lettuce in the hotter periods. We will set the trays in a cooler overnight and let them sit in our covered garage until we see the first signs of germ. After that we move them IMMEDIATELY to a greenhouse with row cover draped over to avoid legginess. The row cover removes just enough of the sun’s intensity to allow for good growth.Hardening Off Grow your seedlings out until large and robust, but do not just jam them into the soil that way (let me learn that lesson for you). You will need to harden them off in the sun for a couple days. Most growers like Ray Tyler (whom I get a lot of good info from and who just offered this short ebook) recommend taking them out in the morning before a sunny day and allowing them direct sunlight. Mist them all day long, at least twice per hour. This will adapt them to the sun so when they hit the field, they are prepared and do not just melt.Shade ClothWe do not use synthetic shade cloth at the moment because we just haven’t needed it yet, but it’s worth considering planting your transplants under shade for the first week or so after transplanting especially in very high volume (hundreds of pounds per week) or very low (a couple for heads for the family). We use other crops—celery, chard, corn, etc.—to do the shading, but this work is still in its infancy so I am not certain I recommend it yet. Also, it requires a certain level of improv that most commercial growers won’t (and probably shouldn’t) be comfortable with. Try it if you can, otherwise consider planting under shade of some form. Preferably in the 30 percent or less range to avoid over leginess.Transplanting and Landscape Fabric Because rot and weeds can be an issue in the summer (especially in the South) a lot of farmers transplant their crops into landscape fabric. Nothing wrong with this. Though it may increase soil temperature, it will also help retain moisture. Either way, when transplanting make sure the soil is cool. I like late evenings or early mornings for planting. If the soil is still warm, considering prepping your transplant holes then watering them well before transplanting. It is always best for the soil to be moist when transplanting.Overhead Irrigation and MistingSeveral times a day I will turn on our overhead irrigation and lightly mist the lettuce at all stages for about five minutes. This creates a sort of evaporative cooling that will cool the plants down and thus reduce bitterness and increase the lifespan of your lettuce. This would work best in conjunction with drip irrigation. For ourselves, we water heavily at night so the roots have plenty of water through hot days. Drip would be better, and keep the roots cooler, but we’re not there yet. Automate all of this to keep it efficient if on a large scale.Harvest Early A.M.To increase shelf life and reduce bitterness, you must harvest your lettuce early in the morning, preferably before sun up. Nothing special here, just get up early and go fast.Cool Down Very Fast Even if you’re harvesting early, in the summer (at least in Kentucky), it can be 75 or 80 degrees out. So getting that warm lettuce chilled quickly is going to be key. I recommend either using very cold water in your wash tubs (if you have to wash it, that is), or simply sticking it in a covered tote into your fridge or cooler until chilled. Shelf life is everything—for customers or for the family, all the above work to get hot weather lettuce should not go to waste by only lasting a few days. Good lettuce, even in the summer, should have at least a 7 to 10 day shelf life.Let me know if you have any questions and please subscribe to our channel. Also consider joining the “Year Round Lettuce Production In Challenging Environments” Facebook group started by Ray Tyler and Michael Kilpatrick if you really want to up your summer lettuce skills!-Jesse