We have made it to July and the heart of tomato season is upon us. We pick tomatoes twice a week, slowly going up and down the rows hunched over coaxing the now knee height fruit from the vines that are currently nearing six feet tall. Both the very early rows in the little sliding tunnels and the main planting in the Big Tops are all giving us fruit from the nineteen varieties we have this year. But not all is well in tomato land, we have a silent thief which will ultimately steal many of the heirloom varieties we all love. It has been four years since we had tomatoes in this Big Top location and we had forgotten that the same thief visited us then as well, but that year we thought it was an aberration, never having had this kind of problem before.
Fusarium Wilt is the culprit and there is nothing we can do about it, at least for this year. It is a soil borne fungus that can live in the soil for years and attacks only tomatoes. Most of the hybrid tomatoes are bred for resistance to it and if you have looked for tomatoes in a seed catalog and seen abbreviations next to a variety description like V, F, N the F is for fusarium resistance. The heirlooms are generally not resistant to it but some are or partly are and that is what we are seeing in the field this year. The yellowing and wilting doesn’t become apparent until hot weather arrives so if there is a silver lining, it is that the plants grew large and set some fruit before it showed up. The bad news is we will have a very short season for some varieties.
The most affected are the high acid yellow Azoychka and the huge, fruity, red and yellow Striped Germans. Next are the green when ripe Aunt Ruby’s German Green and the Green Zebras, they won’t give us much fruit at all. Showing signs but still producing fine are the pink German Johnsons and the beautiful yellow Kellogg’s Breakfast. Fortunately our favorite, the Cherokee Purple, appears to be resistant. All of the red varieties are hybrids and mostly look great except for the Italian Oxhearts that we introduced here three years ago. So enjoy them while we can, there will be tomatoes all season long but less variety as time goes on as the different kinds succumb to the thief.