Tomatoes and Heat

Here in the Inland Northwest, we have gone from 50 something degrees to 99 degrees in a matter of days it seems. Not only does that play havoc with our human bodies but it can have consequences in our gardens.

The common miconception is that tomatoes love heat, the hotter the better. Not so much. High temperatures can cause several problems with tomato production. One of them is “tomato blossom drop.” The tomato blossoms “dry up and fall off the plant before a fruit is formed.”  

 “Tomatoes grow best if daytime temperatures range between 70 F and 85 F. Tomato plants can tolerate more extreme temperatures for short periods, but after several days or nights with temps outside the ideal range, the plants start to focus on survival not producing fruit. High nighttime temps are even worse than high daytime temperatures because the tomato plant never gets to rest.”

 Another tomato response to extreme heat involves its leaves. Just as they respond to very cold temps and lots of moisture with their leaves, you will  notice that some tomato varieties also respond to heat by curling their leaves. That’s a defensive mechanism that attempts to slow transpiration (evaporation from the leaf surface) of water from plant to atmosphere. 

 Specific temperatures at which blossom drop begins will vary from variety to variety. If you experience this, all is not lost, they will eventually snap out it. Water thoroughly early in the morning or put a drip system on at night to keep them well hydrated. Mulch to help retain their moisture. And pray for more temperate weather!Image