Possible Downside

Brandywine OTV - Early July

I have talked about the benefits of a greenhouse for giving tomato plants a jump-start in cool climates.  But I am beginning to suspect a downside as well: many of the plants that spent the past two months in the greenhouse are tall, and starting to bear fruit, but they are yellow and listless, especially now that I have brought them outside.

Leaves are sparse and yellowish-green, without the dark green, springy character of other plants that have been outside all along.  What's more, a number of the plants from the greenhouse have dropped their flowers - usually a sign of stress.  It is hard to research the issue online, but I suspect that moving the plants from the high humidity of the greenhouse and putting them outside may be a bit of a shock.  This idea is strengthened by the fact that a couple plants (Sungold and Green Giant) were kept outside all along and seem more robust.

Since all of my plants were on a similar fertilization regime (inside and out) I do not really think it is a lack of nitrogen. I have fed the plants 2 or 3 times since they went in the ground in early May. I also don't think it's over-watering since all plants have been watered on a similar schedule. So what now?  I have tried foliar feeding to try and give the foliage a boost, but worry a bit about over-feeding.

I am thinking that next year I may use the greenhouses only to get the plants through May, normally a cold, damp month - and then move them outside on the first of June.

The Greenhouse Boost

May 6.  Transplant  Day

First, let me go back almost two months, to May 6. This was when the tomato plants arrived, and I rushed to get 25-30 seedlings transplanted and into the greenhouses.  Conventional wisdom has always been, however, that Seattle's frost-free date was May 15. Not anymore. The average frost-free date here is actually the end of March but yes, there can be cold snaps well into May. But after 30 years of living here (Hardiness Zone 8B - see charts) I am convinced that, with climate change,  the real frost-free date is probably closer to May 1: "official" publications are just reluctant to make the change.

I also had the confidence that I was putting the plants into my two plastic greenhouses, which elevate the daytime temperatures, and tend to lessen the nighttime drop. (We are also very close to Puget Sound which moderates temperatures as well at both ends of the scale.)  However, this year, the fates brought us an unusually warm May. Almost the entire first week of May 6 was sunny and warm, with highs in the 80's. My problem, it turned out, was not keeping the plants warm, but overheating them!

When the sun is shining directly on them, the greenhouses often rise 10-20 degrees higher than the ambient temperature. And since tomatoes do not really like heat over 90 degrees (they will drop flowers and fruit) or high humidity I tend to leave the windows and doors open whenever the temps reach 80 or more, both to keep things from getting too hot, but also to increase healthy airflow.

Starting in a greenhouse has its advantages and disadvantages.

PROS :

*   Higher daytime temperatures speed growth - tomatoes thrive in 75-85 degrees
*   Cuts down on cooling wind
*   Moderates night-time temperatures

CONS:

*   Danger of overheating
*   Excess Humidity
*   When flowers bloom, should be hand-pollinated (no wind, no pollinators)

Complicating this scenario (which would tend to favor greenhouse starts, I think) is the fact that because I ran out of greenhouse space this year, I was forced to put two of them (Sungold Cherry tomatoes) outside.  Today, they are the healthiest, most robust plants I have... More on this later.

Welcome to Summer!

2012 Harvest sample : Black Krim, Brandywine, Green Zebra, Sungold, Sweet Million, Black Zebra

Welcome to the Seattle Tomato Farm!  Actually, what passes as a "farm" here is really just a deck on the front of our house, where we are growing 14 varieties of heirloom tomatoes in containers. 

Wait....Tomatoes in Seattle?  Isn't that impossible? The conventional wisdom, of course, is that it is too cold here, and summer too short - especially near the cold water of Puget Sound where we live. Yes, I had pretty much concluded that myself over the 25 years I've lived here, settling for a handful of tasteless Early Girls and a few hybrid cherry tomato varieties.

Then I discovered greenhouses... Simple plastic greenhouses (like those from Flower House or others) can make all the difference between a fall crop of unripe green tomatoes and an abundance of ripe ones. A greenhouse, carefully monitored to avoid overheating, (more on this later) can extend the brief Seattle growing season, making all but very late (e.g. 85+ days) tomato varieties possible.  

So here's what I'm growing this year:

Brandywine OTV       2

Green Giant                2

Green Zebra               2

Jaune Flamme            2

Lime Green Salad      2   

Mariana’s Peace         1

Paul Robeson             2

RC Mortgage Lifter    2

Sungold                        4

Sunset’s Red Horizon   1

Yellow Brandywine    2

Aunt Ruby’s German Green   1

Pruden's Purple    1

Aunt Ginny's Purple  1

and three Brandy Boy hybrids for comparison  (Burpee)

I bought tomato plants this year, rather than growing from seed, from a farm in California that has an astonishing inventory of heirlooms : Laurel's.  I was able to schedule them for delivery around the first of May, which seems to be the frost-free date here in Seattle  (some 2 weeks earlier than it was when I came here 25 years ago). 

Stay tuned as I update our progress over the course of Summer 2013.