Thursday, 2 April 2009

Talking tomatoes

Posted by: Paul Gardener
A posse ad esse (From possibility to reality)

I’m taking the easy way out today and grouping a couple of posts from my personal blog this week into one entry here. It got a good bit of interaction going over there, and since I don’t get nearly the number of hits that this blog gets, I’m sure that there’s an audience here that hasn’t read these posts. If you have, I thank you for stopping by and apologize for the repeat, but I think it’s worth the conversation and input from others that this site can generate so I’m going with it.

Earlier this week, I asked if there were any questions that any of my readers had that I might be able to help them answer. Someone posed the following question and it started a good dialogue.

I'm curious about your tomato growing method. I think you planted your tomatoes close together (1 ft) and used your trellis system for support. What have been your experiences with growing indeterminate tomatoes in this fashion? Can you talk a little about pruning specifically for your growing method? ~Eric

I think if there’s one thing people first associate with the successful home garden it’s the sweet goodness of a sun ripened tomato.

Well Eric was absolutely right, I do grow my tomatoes in very close proximity (1 sq ft), and yes I am very big on trellising. But to leave it at that would be making the process much too simple, so let me explain.In the pictures above and below, there are two sections of tomato trellising. The tomato above is in the box that is in the back, the one below is in the box in the middle in case you weren't sure. This is last year’s trellis that I tried out. I didn't like it, and am modifying my framework trellis system to have a center beam that I can hold tomatoes on for this year, but this illustrates the method just fine. I do grow the tomatoes in 1 sq foot of garden space, but I have thus far only grown indeterminate plants and they take to this very well. Let me digress for a moment in case you don’t know the difference between the Indeterminate and Determinate Tomatoes. To simplify it, determinate ones will grow to a mature full size plant, usually bushy and not very tall and will then ripen large numbers of fruits that all come ripe at a determined time. Indeterminate tomatoes are exactly the opposite. They will tend to vine, some getting as long as 8-12 feet long and will produce smaller quantities of fruits throughout the growing season. Generally speaking a tomato plant can grow just fine in 6-8 inches of soil, in one square foot of garden bed. The reason they don't is because if they're not trellised they require greater rooting space for structural support for themselves. With the tomato plant trained to a trellis, the support needs are met and the plant just needs to grow. This reduces the space needs of the roots and is one of the reasons I choose to grow mine UP.When I am training the indeterminate tomatoes to grow up, I use a rebar stake that has been notched with a hack saw and tie a string to it. I stick it in the ground right next to the root ball and then run the string up to the top of the overhead beam of my trellis, whatever that is. As the plant grows, it naturally gets "leggy" at the topmost part. As this get's long enough, I just gently wind it around the string which stays in place. You don't want to weave it too tightly or it will strangle the plant, just let the plant know where the string is and guide it around. Here's a close up of one of my San Marzano plants and you can see the string with the plant wound around it.
Now, here's the caveat. This works well for indeterminate tomatoes because they have that natural vineing tendency that I mentioned, determinant tomatoes do not. As I said, they are more naturally inclined to bush and produce a lot of fruit for one harvest than to continue to crank them out over time. This year we are going to grow a good selection of these types as well, and I will not be trellising them. At least not like the other ones. I may work out a loose cage type thing or something to keep them in check, but I am not going to worry about them getting tall. It's not in their nature.
Whatever the means of support you choose to use for your indeterminate tomatoes, they should be pruned. I do make sure to try and prune them pretty consistently. This isn't directly related to trellising, at least not in that I need to do it to get them to grow up or anything. The reason I prune is to maximize the yield as well to limit exposure to diseases. The basics are to pinch off all suckers. (These are usually the branch looking stems that crow out from the crotch formed by the leaves and the stem. They rarely set fruit and if they do it is usually inferior. Secondly, I trim off any old or dying leaves or leaves that touch the ground. Many of the blights and pathogens that tomatoes can get come from soil contact.

There are a lot of good resources online if you'd like more information. I thought I’d include a few of them here for easy access.

• The first one is a great page all about pruning tomato plants. I don't tie mine up like they do, but there's really no hard and fast way to do this so give it a read.

• This page is a .pdf provided by the Colorado state extension Master Gardener program that goes into all kinds of information on Tomatoes. It is VERY good information!
Depending on the variety of indeterminate tomato that you choose to grow, it may well end up growing up over your trellis anyway. There’s nothing wrong with this at all. However, one thing that you will want to keep in mind is when your first frost date is so that you can make a heading cut by removing the endmost section of the stem; doing this will help to force the plant to ripen all fruit that are already set on the plant.
I’d like to ask some of our more experienced readers to take an opportunity to add to this topic in the comments section, or to correct me if you feel I’ve misspoken.

Very best of luck to you all this season!
Grow on!