Garden hints: The tomato family |

Garden hints: The tomato family

Colorado Master Gardener Program
Courtesy photos


Use black plastic mulch for earlier production and higher yields. The mulch also helps controls weeds, conserves water, and protects the foliage from disease spores splashing from the soil.


Trellis or cage tomatoes to allow for easier picking and suppress Early Blight (the most common tomato disease) and psyllids. Trellising allows plants to dry quickly following rains. An ideal trellis is two feet wide and four to five feet tall. It can be easily made from a six and half-foot length of concrete reinforcing wire coiled in a circle.


Avoid crowding plants. Crowding will not increase yields, but will promote disease problems. The minimum spacing for trellised tomatoes is two feet.


Avoid overhead irrigation, which promotes leaf diseases. A soaker hose type of drip irrigation works well under plastic mulch. Tomatoes can also be furrow irrigated with water running in furrows under the plastic mulch.


Except for avid gardeners who use extra protective efforts to realize a few early tomatoes, avoid early plantings. Plant the main tomato crop when the threat of frost has passed and daytime temperatures are consistently above 60 degrees. A week of daytime temperatures below 50 degrees stunts growth.


Over-fertilization causes excessive vine growth at the expense of fruiting. However, starter fertilizer at planting and a couple of weeks later will encourage early growth. (MiracleGro, Peters, and Rapid Grow are examples of water-soluble fertilizers that make great starter fertilizers.)

An additional light fertilization as the first fruits color also will increase yields and resistance to Early Blight.

Blossom drop

Hot, dry summer winds can cause blossoms to drop. Inconsistent watering contributes to this condition.

With night temperatures below 55 degrees, blossoms that open the following morning will not have pollen, and blossoms will drop. For example, there is a 50/50 probability along the Colorado Front Range that any given summer night will too cool for pollen development.

For early production and in cool locations the “blossom set sprays” effectively improve yields.

If daytime temperatures rise above 90 degrees by 10 a.m., blossom opening that morning will abort.

Blossom-end rot

Irregular watering and over-watering causes development of a dark, leathery area on the blossom end of fruits. Water consistently in a deep, improved garden soil and mulch will help prevent this condition.

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