Saturday, May 11, 2013

Gardening: Dryfarming Tomatoes

This is supposed to be a bad water year. The reservoirs are percent? Sixty percent of normal for this time of year? Somewhere low. The snowpack is lousy. It's gonna be dry. So this seems like the perfect year to try dryfarming techniques--dryfarming being the growing of crops without any added water.

So I'm going to plant a few tomatoes tomorrow according to the following plan:
  • I'll space them at least four feet apart. Each tomato will "own" the entire width of its four-foot-wide wide row, and will be at least four feet from the next tomato down the row. The paths between those four-foot rows are two feet wide, so that means that they'll technically be six feet apart in that direction, though path footage doesn't quite count.
  • I'll put them in rows that march toward increasing afternoon shade--at least, I will if I get around to tilling a little more land; the shadier area probably won't get planted until next weekend. This isn't necessarily a dryfarming practice, but it'll be interesting to see how the plants fare with more shade versus less.
  • I'll plant them deep, with foliage along much of the stem snipped off and the stem buried up to the last big tuft of foliage at the top. When I Google dryfarming tomatoes, this is recommended, I assume so that you can get those deep roots started from the very beginning. (And maybe having minimal foliage during transplant-shock time is also good?)
  • I'll plant them into weed barrier/landscape fabric. The soil has already been amended with some manure and fertilizer and tilled. I don't know if tilling is good for dryfarming, but it's done.
An aside: The landscape fabric is not actually a dryfarming practice--I think. Dryfarming recommendations are that you prevent absolutely all competing plants--no weeds, no cover crop, no nothing. But the usual method of doing this is to grow in bare frequently-hoed dirt, and in fact a few inches of "dust mulch" to break the capillary barrier between the deeper soil and the surface, so that water doesn't wick up and evaporate into the air.

I was a little concerned that landscape fabric would keep that whole capillary thing going. However, there are studies that dispute the dust mulch theory, and nobody seems to dispute the idea that weeds will steal water from the crop. And I know my slack weeding habits. So weed barrier it is. We'll see how that works out.
  • I'll stake... OK, I'm not sure what my plan should be here. I don't have to decide before tomorrow; tomorrow I'll just pound a tall stake in the ground near each plant. But does dryfarming care whether you do the one-stem thing, pruning off extra branches? Or does it prefer a bushy plant? Or does it prefer that they just flop on the ground? More research is called for.
  • I'll water deeeeeeeep the day that I plant. That seems vaguely counter to the dryfarming thing, but nobody seems to be suggesting that you don't water when planting, and I don't want a shallow layer of damp soil encouraging shallow roots, and I'd guess that the longer that dose of water lasts, the better for the plant trying to recover from transplant shock. Now, in theory I should discover that there's retained winter water a few inches down, so I shouldn't have to add that much water. We'll see. I'm also thinking maybe I want to water at each plant's spot, maybe with a bubbler running low for a good long time, rather than watering deep and wide and covering each tomato's whole four-by-four space.
  • After planting, I'll have to restrain the urge to keep dosing the seedlings with water. If they do look on the verge of death and I decide that I must water, I'm thinking that I want to water deeeeeeeep again, after as long a wait as possible, to keep them from getting addicted to regular fixes of water.
  • According to my reading, I should have started with early tomatoes, like Early Girl. I didn't. Oh, well.
  • I'm hoping for at least one more good rain, while the tomatoes are settling in.
One thing that will reduce the validity of this as an experiment is that the tomatoes will start just a few feet from where the strawberries end, and the strawberries are going to be given a decent amount of water, some of which will no doubt drift toward the tomatoes. For tomato survival, it's probably good that the tomatoes with more sun will be closest to this stolen water, and the ones with more shade will be further. For scientific purposes, there are too many tangled factors to make this a decent experiment.

That is all. Please wish my tomatoes luck. They're eyeing me suspiciously from their pots on the deck.


  1. I'm looking forward to hearing how this works out for you.

    I think Novella did this a few years back (let me check...wait a minute...okay I found it...)

  2. Ooh! Thanks, Carol! That's very useful. I'm not sure how to translate the California calendar to the Pacific Northwest one, but it's very interesting to see how someone else did it.