Early Tomatoes

 

        By Steven Hightower, Sonoma County Master Gardener

I’m going to do an experiment this year in an attempt to grow tomatoes that ripen much earlier than tomatoes normally do in Sonoma County. I opined in last year’s article “Tomato Tales” that I had “learned from experience that in my location, on Sonoma Mountain in Glen Ellen, the best results were obtained waiting to plant until the second or third week in May” which is true if one is growing tomatoes using standard methods and techniques. And that timing results in actual ripe tomatoes arriving in late July or early August, at best. It’s true that tomato plants do not grow well until the soil is warm—usually quoted as at least 55ºF, and that the optimum growing temperature for tomatoes is above 60ºF.

But, where there’s a will there may be a way, and I've been reading recently some interesting articles and posts on super early tomatoes—strategies, even in snowy parts of the country, to have ripe tomatoes as early as May, or perhaps early June. That research has turned up a number of tricks and techniques that may make earlier planting, growing and harvesting successful.

The first and most obvious thing will be to plant tomato types that are more cold-tolerant than the norm, and that have shorter ripening periods. For the very earliest tomatoes it's necessary to grow from seed, only because there are no tomato plants available at nurseries early enough to get started. This is straightforward for gardeners who normally do this, but I haven't developed an interest in seed germinating. So since I’ll be buying the earliest tomato plants that are available at nurseries, or at the farmer’s markets, and not growing from seed, I’ll be limited by what’s available. But surely Early Girl, and possibly Stupice will show up, and I’ve read that Glacier, Polar Star, Polar Baby and Early Pick all do well planted early, so I’ll try one or more of them if available.

Preheating the soil by covering it with black plastic a couple of weeks or so before setting out plants should help (I’ll be sure to anchor the edges of the plastic to keep it from blowing away.)

I’ve long been a believer in burying both the root ball as well as much of the stem of the tomato plant in a trench, rather than just putting the plant base in a shallow hole, so I’ll continue that practice. To do so you dig a trench instead of a hole, and lay the plant in it, gently bending the top of the plant vertical, and covering all but the top leaves with soil. Extra roots develop along the buried stem increasing the plants ability to take up water and nutrients. I always throw in a handful of bone meal, a handful of agricultural lime (to help prevent  blossom-end rot) and fill the trench with half soil and half compost for organic nutrients.

A very clever-sounding trick I ran across is to dig, a few days before planting, a hole about 6-8 inches lower than the tomato will be planted, and create a mini-compost pile, with some kitchen vegetable scraps, grass, leaves and perhaps some straw. Compost piles generate heat, and this method is said to create a small ‘ground heater’, directly under the early tomato, that will provide some warmth for a period of weeks after planting. This is a very intriguing thought, and another tip I'll have to report back on later in the season.  I may have to add some nitrogen-rich fertilizer as the composting process is a net-user of nitrogen.

Another interesting technique is to surround each plant with thermal mass that will soak up heat (from sun and air) during the daytime, and re-radiate that heat at night. One variation is placing three one-gallon clear plastic jugs or five to six two-liter soda bottles filled with water around the newly planted tomato. Another writer suggested a commercial product called Wall o' Water, which is essentially a water-filled plastic curtain which surrounds the plant. A similar product is called Red Tomato Teepees--the same surrounding curtain in red plastic, and yet another at Park Seed Co. is Kozy Kotes. Online reviews seem to indicate that they work fairly well, but are a bit tricky to learn to set up and fill. I'll probably stick with the two-liter soda bottles.

Depending on the weather at the time (rain, cold snap, frost potential) I may build a lightweight frame around the bed, and cover the plants at night for the first 2-3 weeks after planting. If left during the daytime due to a colder snap or frost, the plastic should be vented to avoid overheating from sun.

Then there's red plastic tomato mulch--a bit of a cult craze from a few years ago, jointly developed by the USDA and Clemson University*.  Montana State University did a 2-year study that found that red mulch did speed ripening in tomatoes. The red plastic actually reflects far-red light wavelengths upward into the tomato plants. This is said to trigger the release of a natural plant protein that stimulates more rapid growth and development. The definitive website on red mulch is: http://plasticulture.cas.psu.edu/summary2000.htm .

*(In 1985, Michael J. Kasperbauer and Patrick G. Hunt (USDA-ARS Soil and Water Conservation Research Lab, Florence, SC) conducted a tomato production trial with plastic mulch in cooperation with Dennis R. Decoteau from Clemson.) 

So how will this fare? I’m completely in the dark. Others seem to have had luck, and in parts of the country with much more severe spring weather. The combination of weather—sun, temperature, rain—from mid-March to mid-May, combined with the efficacy of a combination of these tricks will tell. But we should know a fair amount by the time we’d just be setting plants into the ground anyway, so that can’t be bad. If anyone has personal experience with early tomatoes in Sonoma County, please email me at mgsonoma@ucdavis.edu.  I’ll be reporting back to you on this later in the year! 

A good supply of tomato starts is available at many places in the County.  Try Harmony Farm Supply in Graton, Cottage Gardens in Petaluma, Sonoma Mission Gardens in Sonoma, and Emerisa Gardens, outside Sebastopol, which will be carrying vegetable starts for the first time this year. 

Here's the chronology of how things went

I planted the rest of my tomatoes on May 15th, as usual. They are all fine, growing, and on average, around 8-12 inches high--just beginning. The early tomatoes, on the other hand, are fairly lush, close to 3 feet high, and two have set tomatoes that are beginning to show color.  So we can at least preliminarily conclude that using four out of the six 'tricks' discussed in the original article (all save the soil heating plastic and red mulch) that the harvest point for tomatoes in Sonoma County can be moved up fairly significantly.

June 1, 2009

Our early tomato experiment shows some promise so far, if not perfect success. I was able to find Early Girl, of course and Stupice as early varieties, and planted them the end of the second week of March--not quite as early as I'd planned, but still two full months before I normally plant. I did not preheat the soil with black plastic, but did create a small compost pile under each of the three test plants. I planted them with about half the stems covered, in the 'trench' method. Three 2-litre soda bottles filled with water as heat sinks went around each plant.

In the ensuing weeks, we had a cold snap, though not a hard freeze, and some rain. I covered a sparse frame around the plants with clear plastic for about two weeks during that time. I mulched fairly heavily, both for heat retention and weed suppression, and watered a bit less than normal, every few days. I've yet to try the red tomato mulch so cannot report on that.

June 16, 2009

The three early plants are physically much larger and further along than those planted in May, and there is lots of fruit on them, in various stages of ripening. When I looked yesterday, three small Early Girls were ripe, so I picked them. That's just under 90 days from planting in mid-March, and will no doubt be between a month, and a month-and-a-half earlier than my plants put in at the normal time. So qualified success--again amount and length of crop yet to be determined. Refinements next year will focus on trying to get that almost 90 day maturity down a couple weeks in that early period (early girls are supposed to be something between 60-70 days)

August 15, 2009

For me, the EarthBox experiment was a bust. The tomatoes planted in them were not so great (see above caveat about the year, however). The zucchini didn't fare as well as they do in the ground. And the watering is not the snap claimed. The watering basin seemed to need to be filled about every other day, for the plants not to dry out--lots more work than drip.

In the end, I think there's just not enough root area in them for normal tomatoes, zuchinni, and other veg that throw pretty good roots. Perhaps they're a solution if you have an apartment, or a small patio, or no other place to put vegetables, but as an alternative to a garden, or raised beds, EarthBox is a non-starter.

August 22, 2009

We can report good, and mixed results at the same time. It's been a generally lousy year for tomatoes--reports from all over are bad. So on the good side, the early plants continued to be significantly larger and more vigorous than my plants planted mid may, right up til now. They're very prolific with fruit, and are fantastic tomatoes. Like others I've had a terrible tomato year with all those later plants--not  much fruit, very late ripening.
 
On the mixed side, we didn't actually get tomatoes off the early planted plants until the second week in July, and not a huge amount then. By early August, they were starting to ripen in goodly amounts, and since then they are great producers. Again, the later-planted plants aren't. But relative to the year, and other tomatoes this year, and by all the stories I've heard from others, the early planting was a qualified success--much better than others, BUT no tomatoes by the beginning or even middle of June.