Direct Seeding, TM Style
by Christopher Covelli, Farmer/Owner of Tomato Mountain
Chris rolling the field beds before the rain comes in
There are two ways we get crops started at TM - we either sow them in flats where they grow until they are ready to be transplanted into their hoop or field bed, or we directly seed into the hoop or field bed where they’ll complete their entire growth cycle. Late summer through fall is the time of year we do most of our direct seeding, so this week, I decided to give you a primer on how we do it.
The first step is to remove any vegetation currently in place. Where tomatoes were grown previously, we need to chop the long and tough stems with an aggressive bush mower, called a flail mower, that can reduce the vegetation to small bits and pieces. We do the same thing with zucchini, peppers, eggplant, and other “big stuff”. We then add the equivalent of 50 tons of compost/acre (a little bit less than 1” thick).
If I’m preparing the ground for carrots, the next step is to go over the beds with a field cultivator, a tool with chisels that go down about a foot deep to loosen the soil at depth and help the carrots grow long and straight. This is probably the hardest single thing to do on the tractor because it’s hard to keep one’s bearing and go straight when working the ground so deep, removing all reference points at the surface. After “cultivating”, the beds are again tilled, to make them flat, to set up for the next step.
Rolling beds is pretty straightforward, accomplished with a simple 4’ lawn roller we pull with a tractor. When we direct seed spinach in the hoops, we use a smaller, hand pulled version of this that requires two people to maneuver and operate. It’s important to have a firm surface for the seeder to work on. If it’s too loose, the seeder sinks in too far and doesn’t cover the seeds properly.
At this point we can “pretreat” the beds by germinating as many weed seeds as possible. We can irrigate every day for a week, allowing weeds to germinate, and then flame the bed surface with a propane torch. This method, known as “flame weeding”, is a great way to get rid of lots of weeds fast before the cash/vegetable crop even gets sown. It takes at least a week to get most of the weed seeds germinated and “out of the ground” enough to get at them with a flame, Germinating seeds, and the soil around them, need to stay moist for success, so it’s important not to let the soil dry out in this process.
There are many variations on the potential timing of flaming. It’s also very popular to plant the vegetable seeds into the bed somewhere around 4-7 days after initial rolling/watering. It’s important to keep the weeds continually wet underneath the surface with frequent waterings, so they keep germinating, and choose a time to plant the veggie seeds when only the surface has just barely dried out. There are usually a few hours when all these conditions happen simultaneously, and the veggie crop can be planted when the surface is dry, but it’s still damp just underneath, so the weed seeds keep coming up. As long as we flame before our veggie crop emerges, we win by killing lots of weeds in very little time, resulting in much cleaner beds.
Whenever it gets done, there is the seeding itself, accomplished with a basic precision seeder that controls seed depth and spacing. Getting the adjustments right, so that the soil “flows” over the seeder mechanism and puts seeds down at the proper spacing, is key. Soil moisture and the amount of residue from the previous crop play a role in how well everything flows and works. Balancing the variables to get a firm seedbed that the seeder rolls down easily is the goal.
Vegetable seeds need to stay wet until germination too. For things like carrots it takes 10+ days of watering. Spinach is quicker so we water it for 7-10 days after sowing.
It can be tricky to get the timing for all of these steps down just right, particularly in the uncovered sections where we have to watch the weather closely, but it’s worth the effort to establish a full and weed-free stand.