Do You Want Tomatoes or Not?

Slicing tomato brought to the University Orchard several years ago. Might not get the same production year after year when planting unproven varieties.

           The choices you make when fertilizing tomato plants right now might be the difference between having tomatoes to eat or not. If we have a long drawn out cool spring with temperatures in the 80's, it won’t make much of a difference. You just might have an abundance of tomatoes. If we have one of those springs that jumps from cool weather to hot weather you will have fewer tomatoes. Tomatoes stop setting fruit when daytime temperatures are consistently well above 90° F. But you can harvest into June.

Nitrogen Fertilizer Management

            It’s all about nitrogen fertilizer management. High nitrogen fertilizers, like 21-0-0 or fish emulsion, guano or blood meal can cause tomato plants to grow abundantly with dark green leaves during warm weather but push flowering and fruit production a little longer than necessary in the spring. Once flowering and fruiting begins, rampant growth subsides usually keeping tomato plants from growing too rapidly. However, using high nitrogen fertilizers soon after planting can cause a lot of top growth and, along with that, delay flower and with it fruit production.

Start With a Pre-Plant Fertilizer

            If you are planting into a dark, rich soil mix then don’t fertilize with anything. If this soil mix is one year old, I would use a starter fertilizer  at the time of planting and not fertilize again until flowers and small fruit are seen. Those who use conventional fertilizers might use 16-20-0 as a starter fertilizer. Ideally we are looking for a fertilizer that contains about twice as much phosphorus as nitrogen and still delivers some potassium. In fertilizer lingo this would be as close to a 1-2-1 ratio.

Organic Fertilizers

            Those who prefer organic fertilizers might use bone meal mixed in the soil at the time of planting and follow that with an organic foliar spray when needed. Fish emulsion mixed with water or compost tea sprayed on the foliage when tomato leaves become light green.

             The same principle holds true with garden soils. If you mixed in a rich compost before planting, then don’t fertilize with anything more until fruit is first seen. If the garden soil is a little worn out from last season’s harvest, then use a starter fertilizer at planting time.