(MANHATTAN)—Tomatoes are a staple of most home gardens in Kansas and it is just about the time of year for many to be ripe and ready to eat. Those still in the growing stages can sometimes suffer from over-fertilization in homegrown gardens.
“In order to yield well, tomatoes need to be side-dressed with a nitrogen fertilizer three times during the season,” said Upham, a horticulture specialist with K-State Research and Extension.
“The first side-dressing should go down one to two weeks before the first tomato ripens,” he added.
The most common nitrogen-only fertilizers for tomatoes include nitrate of soda, urea, ammonium sulfate and blood meal. Upham suggests the following rates for each fertilizer:
Nitrate of soda (16-0-0). Apply 2/3 pounds (or 1 ½ cups) fertilizer per 30 feet of row.
Urea (46-0-0). Apply four ounces (1/2 cup) fertilizer per 30 feet of row.
Ammonium sulfate (21-0-0). Apply one-half pound (1 cup) fertilizer per 30 feet of row.
Blood meal (12-1.5-6). Apply 14 ounces (1.75 cups) fertilizer per 30 feet of row.
The second side-dressing should be applied two weeks after the first tomato ripens, and the third should be one month after the second side-dressing, Upham said.
New potatoes are maturing as well now in many Kansas gardens. Right now, they should be the size of a walnut.
“To check if they’re ready, pull soil away from the base of the plants to see if the tubers are the desired size,” Upham said. “If they are, dig entire plants and allow the skins of the exposed tubers to dry for several hours before gathering.”
Upham said the young potatoes are very tender and prone to the skin ‘slipping’ if they are not allowed to dry.
“Even then,” he said, “these immature potatoes will not store well. Red-skinned varieties are often preferred because they are the earliest to produce.”