The Tricky and Delicate Art of Grafting Tomatoes

~Notes from the field SongHaven Farm~

It’s raining, sleeting and occasionally snowing here at 6800 feet elevation in Cahone today. A classic stormy spring day on the great sage plains and I am elated that I have indoor work to do around the farm.

For most of us in the high desert of Colorado we use high tunnels (think unheated greenhouses or poly-tunnels) to get our precious hot crops to market in a timely fashion. For instance, without a tunnel the typical tomato crop wouldn’t start yielding till the beginning of August and then will start to decline in production in mid-September when the weather gets cooler. With a unheated tunnel we can push that production up a month and possibly get tomatoes by the beginning of July. This gives us an additional four weeks of fresh tomatoes for our customers during a period of optimal temperature and growth.

One downside to growing these hot crops in a tunnel is that space is limited and often, unless you are a farmer with many high tunnels or moveable tunnels, we end up planting the same crop in the same space. This can lead to problems of plant disease that weaken our crops and yield. With this in mind, we are doing a grand experiment here at SongHaven Farm this year – side grafting tomatoes!

Yes, indeed, it is as tricky as it sounds. To graft tomatoes you must start both a “rootstock” plant, and the plant that is your “scion,” or fruit part of your plant. Ideally they will grow at the same rate till grafting time comes. When that time does come you try and match up the stem size of your two plants and then the delicate business of tomato surgery begins. Grafting tomatoes is very similar to grafting apples – the idea is to cut off the top of the rootstock and then slice into both stalks and fit the fruiting tomato into the rootstock stem and clamp it together. After the plant is potted up it is left in a dark, high humidity space with a temperature of around 70 degrees for three nights. Once it comes out of its healing chamber it is then “weaned” from the fruiting tomato stem and root system and onto the rootstock stem. Very tricky business indeed. Adding to the complexities, here at SongHaven Farm we can’t use heat mats to keep the environment warm (like most farmers) because we are off the grid and therefore have to use a wood stove to heat our healing chamber. It’s a whole other ballgame…whew!

So, why are we going through all this trouble? Well, call me insane, but I like a challenge and I also like to experiment with new things year to year. I am hoping that this experiment will yield a greater abundance of great tasting tomatoes (because we just can’t get enough of them) and give our tomatoes better disease resistance. We’ll let you know how it goes….

Rootstock and Fruit part of tomato grafts.

Keeping the graft joined and healing.

Pot up the graft, keeping warm and cool as it binds.

Newly grafted tomatoes!