CONTROLLING & SUBDUING TOMATOES in the GARDEN

New Gardener Surprised by Unruly Vines

Feral tomato escaping its cage,
Source: scientificgardener.blogspot.com

Recently I spoke with a new backyard gardener who mentioned to  me that last year his tomatoes  had gone wild  even after he had put them in cages. The vines  got "tangly" and had refused to stay in their cages. Had his tomatoes really gone feral?  

Experienced tomato gardeners, of course, know there are two kinds of tomatoes: determinate and indeterminate. Determinate plants, e.g. Valley Girl, Defiant and Celebrity, typically grow to a height of around 3 - 4 feet, blossom and then all their fruit   ripens within  the space of 1 - 2 weeks.  Indeterminate plants, e.g. Beefsteak, Big Boy and most Heirloom varieties,  can grow  numerous vines from suckers that also turn  into vines of 6 - 12 feet or more. Both types can benefit from pruning; and for most of us with limited garden space, some additional  kind of vine management is also required.  Without gardener intervention neither type will look like the neat and tidy tomatoes you see in most Internet  or seed catalog pictures.

Now in fairness to those of contrary opinion, I acknowledge  there are gardeners who claim that except for removing the lateral shoots from the bottom 10" of any tomato to promote better air circulation, pruning is not necessary. And, I also admit I never  pruned any tomato growing in my uncle's fields when I was younger,  but my uncle had a lot of space and a lot tomatoes and we just let them sprawl on the ground. We lost some tomatoes to slugs and to our clumsy footwork, but we were satisfied with our yields for market.

The arguments in favor of some kind of pruning include that it increases the size of individual fruits by reducing the energy and nutrients otherwise devoted to plant growth,  allows for more exposure to sunlight   further minimizing the risk of disease from too much dampness, and finally pruning  simply fits the plant(s) to limited garden space.  However, pruning  implies that you also   do employ some kind of vine support. Keeping the fruit off the ground also decreases fruit loss from disease and damage from slugs and, maybe most importantly, avert some backaches later during harvest.

Cages & Staking for Determinates

Cages sometimes need to be staked to hold the fruit load.
Source: oldworldgardenfarms.com

By their nature, determinate tomatoes need less pruning to fit garden space then indeterminate varieties. The Internet is loaded with tomato pictures exhibiting various gardener techniques:  single and multi-stick staking, inverted and pyramidal cages, simple vertical fences and all kinds of trellises.   My experience with Celebrity tomatoes  is that cages generally need staking because heavy  fruit loads require that cages may also  need propping  up    even when I have limited plants to 4 shoots.  I also space the plants at 3 - 4  feet  intervals instead of the commonly stated 2 feet for determinate tomatoes because I like to be able to move around my plants easily as well as  to enable good air flow.

Dealing with Indeterminate Varieties

As we mentioned earlier, indeterminate tomatoes can produce long vines, and the vines will keep on growing and  trying to set new fruit until killed by frost.  Towards the end of a growing season it's a good idea to  clip off  vine leaders to stymie new growth and encourage   the plant to focus its energy on existing fruit development.  Because indeterminate vines can easily exceed 12 feet (20+ ft is not an uncommon length in green houses if a grower has pruned a plant to a single vine), it is necessary to provide a way to support (actually, suspend) the vine.  Cages are not a good choice for indeterminates. The cages available from many big box and retail nurseries, even the large economy size cages, are simply too small in my opinion, and way too expensive.

Wow! Overhead trellis for a single tomato plant.
Source: mothernaturenetwork.com

If you trim  intermediate vines just to fit your cages, the yield will be greatly reduced; if you don't prune, the vines will continue to grow and either cascade down to the ground or land on an adjacent cage - soon creating a tomato vine jungle.    Staking is also possible, but requires you to make or locate stakes long enough to hold long vines. With stakes you can control vine spacing better; otherwise they really offer little advantage over  cages.

That said,  some kind of trellising or fencing seems to be  better approach. Trellising also allows your imagination to get some exercise in design.  A trellis can be as simple as growing a tomato along a fence (assuming you don't need to worry about    either  wild critters or neighbors, both of whom probably like tomatoes).   Or,  a trellis can be a simple A-frame design with its cross pieces lashed  together for a season.  A-frame trellises are  popular in small gardens because they are quite stable, but  reaching some areas might not always be easy.

Simple A-frame trellis.
Source: freescortpost.com

I think  a simple vertical frame (below right) is better. It requires less material and less space. You can also reach both sides easily. The major drawback of  a vertical design, however, is that the posts need to be firmly set because they will be exposed to  dynamic loading: vines + fruit multiplied by wind.

For either an A-frame  or a vertical design you have choices about what to use and how to attach  cross pieces. In either approach you can use  cord, netting, wire cable or even sections of fencing   attached to the supporting frames to bridge the openings between posts. Another variation, if you choose to prune to a single stem, is to simply attach a top cross piece between posts and suspend  single strands from it for  vines.  The strands must be  firmly secured at the bottom to keep the vines from blowing in the wind.

Simple vertical trellis.

Source: tomatoville.com

Last Words about Pruning 

For determinate tomatoes in cages I usually try to limit a plant to 4 stems, but I do sometimes break my rule and go with 5 because I leave more  space than is commonly suggested;  and because I tend to have more tomatoes than I have cages, I keep a supply of stakes anyway. But that's pretty much all I do. Remember, the stems of these guys only grow to a set height and a set number of fruit.  By removing their side stems you are restricting how many tomatoes the plant will produce.  

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The indeterminate type, as already mentioned, are a different story. They will keep on growing and trying to start new vines.  These start out as "suckers" (see diagram below) at a node just above a  leaf stem.  When you are growing this type of tomato, your


trellis or frame decision will determine what your pruning approach will be.  Allowing for 4 - 6 suckers   to develop  into vines is common.  But if you think your growing season is long and only have a couple of plants, then you   might think about letting a couple  more lateral vines develop.

For commercial growers using support systems in either greenhouses, high tunnels or   the field, a 4 vine approach seems  to be considered the golden mean in that it balances  a profitable yield against  the labor costs involved in  attaching additional  vines to frames and  regularly pruning the to remove  their own  new suckers.


And remember...

"A good garden may have some weeds." - Thomas Fuller (1608 - 1661)