Onions

The warmth of the last couple weeks finds the gardens bursting with growth. Our 8o degree plus temperatures and cool nights is as to much to the garden's liking as to our pleasure. Its nice out there and plants are in a full growth spurt.

In the vegetable garden this is the make or break time before the heat of summer when most of the plants will either stop, drop or slow to a crawl. Of all the vegetables we grow two need special and diferent care for success. Onions and tomatoes are as popular as they are different.

Aside from the obvious that one is a bulb and the other is a botanical fruit, differences go much deeper. These are the day/night, the chocolate/vanilla the yin/yang of the garden.

Onions originated in the Afganistan region of the world. Cultivation is traced back to the 3200BC with Egyptian references. The onion found its way into all cultures from its culinary uses to the flower bud being the model for minerets in Asia to the cure for Beriberi cited in Henry Dana's classic 'Two Years Before the Mast.'

Tomatoes arose from the wester slopes of the Andes and did not make it around the world until much later when the Spanish and Portugese explorers found it and took it around the world. Even with its relatively late introductin to the palette it now ranks as the number one vegetable grown in gardens. The onion, even with the all its history ranks much lower in popularity.

In the desert we find the 'sweet' onions quite adaptable to the alkaline conditions and short summer days. Tomatoes, though easy to grow elsewhere offer a real challenge here. Anyone can grow a tomato in the midwest; its takes a gardneer to get good tomatoes here.

Care for these differ greatly. Onions need lots of nitrogen and no, repeat no sulfur. Sulfur triggers the pungent flavor so choose a nitrate form of nitrogen or an organic form to avoid sulfur. (If you used sulfur in preparing the soil, sorry, wait till next year.) Not supply copious amounts of nitrogen to the onion you will gow beautiful mineret models and poor bulbs. While the flower buds are interesting they don't eat as well as a nice thick, juicy, sweet bulb.

Tomatoes respond negatively to too much nitrogen and love sulfer; just the opposite of onions. Sulfer should have been mixed in at the soil preparation time. Spoon feeding tomatoes with a water soluable fertilizer every two weeks or more is a necessity. Most of the water soluable fertilizers, without illegally specific naming products, turn the water blue or green when mixed. Manure or compost teas serve equally as well Letting them go with out a balanced fertilizer or just supplying nitrogen will reduce the fruit number and quality emensely. Another trick is to give each tomato plant a heaping tablespoon of gypsum per week. This will help to counter a calcium defiency in tomatoes called 'Blossom End Rot.'

There remain only a couple short months of ideal growing weather before summer. Take advatage of this beautiful weather and fertilize your gardens so the plants can use the water, sun and mild temeratures to grow as much as possible. Remember, don't get the onion and tomato fertilizer programs confused - Nitrogen, no sulfer onions and low nitrogen and sulfer for tomatoes.

Or was it the other way around? Enjoy our great gardening weather!

Written by Terry Mikel, College of Agriculture and Life Sciences, the University of Arizona, 602-470-8086.
Material originally appeared in Arizona Republic
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