What happens when an unexpected late spring freeze kills your frost-tender vegetable plants? Most likely, this means a trip to the local greenhouse to purchase replacement plants. What if the killing freeze was widespread and it struck in mid-June though?

A Late Last Frost

In my area of Ohio, conventional gardening wisdom dictates that by Memorial Day, it’s safe to plant the vegetable garden. This is based upon our average last freeze date of April 29th and the average last frost date of May 10th. 

By the end of May the soil has warmed, and the overnight temps are usually above 50 degrees F. (10 C.). If a cold snap does bring in chilly air, covering transplanted seedlings with a light sheet is often sufficient protection. Yet, this wasn’t the case in 1972.

I was a child then, but I remember the havoc an overnight freeze on June 11th caused for gardeners in my area. My parents, like many gardeners, woke up to find their tomato, pepper, and cabbage plants severely damaged or killed by an overnight cold snap.

The problem was, by mid-June local nurseries had clearanced and sold out their remaining vegetable seedling stock. It was also much too late to start new plants from seeds. Luckily, my parents were able to acquire extra tomato plants from a gardening friend. Not all gardeners in our area were this fortunate. 

How to Protect Plants from Frost

This childhood memory has left me wary about unexpected weather events, especially since late frosts and freezes hit our area every few years. So far, I’ve been able to protect my garden from these unexpected events by following these precautions:

• Hold off planting until the soil is warm – Soil retains heat and helps protect tender transplants should the air turn cold.
• Monitor the weather – In late spring and early summer, I check the forecast on a daily basis. Cool daytime temps and a clear sky at dusk can be a warning sign that temperatures may drop overnight. 
• Proactively protect the garden – I’d rather waste time protecting the garden when it didn’t need it, than not protect it and have to deal with cold-damaged plants. 
• Be prepared – Nobody likes clutter hanging around, but I find having a stack of cotton sheets to cover the garden in an emergency can mean the difference between saving the plants and replacing them.

Although I have successfully thwarted Mother Nature in the past, I’m not certain these tips would protect my garden should the 1972 forecast repeat itself. However, I do have one more trick up my gardening smock. 

Each year I plant an early vegetable garden in containers. These pots can easily be sheltered indoors should cold weather threaten. Plus, I’m rewarded with ripe tomatoes and harvestable-sized peppers much earlier in the season.  

While my container garden doesn’t produce as much as my inground garden, it does provide sufficient quantities of fresh veggies for table use. I like to think of my container garden as an insurance policy. I might never need it, but it’s good to have if I do.