How to extend the garden season

Portable greenhouse

Saturday, November 18, 2017

When temperatures start their downward trend, there are ways to protect your crops and extend the season.  This works for either the fall, winter or spring.  Give them a "coat" of sorts to protect them against those drops in temperatures.  There is also the old time technique of a hot box. 

What can you do to extend the season?  

*Throw a sheet or plastic or other light weight cover over them when the cold snap comes in.  I remember my grandmother putting a sheet over hers.

*Buy “cloches” which are little plastic or glass bell shaped covers and place over each plant.  

*Put a portable greenhouse over them. 

*Use wall of water.  They really do work!

*Another option is to plant them in pots so you can bring them into the garage when temperatures get into the 30's and 40's.
*I am keeping some plants on the covered deck.  This will keep them protected from frost, but tender plants like basil won't make it through nights at or below freezing on a porch.

*Add mulch.  Mulch will raise the garden bed temperature and also keep the ground temperature more moderate, less swings.

Cloche

The watch-out for covering with plastic, cloches or greenhouses is that you can fry your plants if you leave them closed up during sunny, warmer days.  The cloches that I have come with vents that I can leave open, but I have had casualties even with leaving the vent open.  My portable mini-greenhouse has a zipper opening that makes it easy to vent.  For plastic sheeting, you will either have to remove it when it warms up or have a way for the ends to be opened to allow cooler air to circulate and keep the plastic off the plants themselves. 

Surprisingly, I had some peppers under cover and others that were not, and the uncovered peppers did just fine, even when the temperature dropped to 28 degrees.  Getting down into the teens would kill any pepper plants left outdoors.

For the peppers, tomatoes or eggplants that you loved, you can overwinter them indoors because they are tropical perennials.

I have used all in the garden.  There are pros and cons to each.  The covers can blow away if not weighted down.  The cloches and mini greenhouses can get too hot on a sunny day if not opened.  If you work, it is hard to time opening just after the sun rises depending on when you need to be at work.

How long can a cover extend the season?
Tunnels (row cover with hoops) and cloches- 6 to 7 weeks for broccoli, cabbage and greens.  4 weeks earlier for melons and squash
Wall of water-Up to 8 weeks for tomatoes and peppers.  Just be sure that the ground and wall of water is nice and warm before planting these warm weather lovers.

Mini greenhouse-Up to 8 weeks.  I put jugs of water inside my mini greenhouse to moderate the temperature inside.  I have had my lettuce and greens last all winter in the portable green house.

Cold frame or hot box/bed-This is a technique I have not tried and it has been around since glass was made.  My Grandpa had several that Granny used every spring.  

Manure hotbed-Horse manure with straw bedding used to keep the hotbed warm to get warm season crops seedlings started or can be used to keep the cold crops going through the winter months.  Back in the day, manure hotbeds fed Paris through the winter.

Hotbeds are dug into the ground a couple of feet and lined with bricks to act as an insulator.  Several inches of horse manure with straw bedding was placed in the bed, wetted, allowed to age a few days, then topped with 8' of soil and when the temperature is between 70-80 degrees, seeds are planted.  Close attention has to be paid with opening and closing the window type lid so that the plants don't overheat on warm sunny days.

Of note, fresh manure can have the bad microbes like e. coli.  It is recommended to fully compost any manure to eliminate the risk and to "cool" the manure so as not to burn the plants.

You can use without the manure.  These are called cold frames.  The temps won't stay in the 70's day and night like they will for hot beds, but will sustain cold loving crops through the freezing temps of winter.


For more on cold loving crops and gardening:  
You can garden year round in small space  
Homegrown, organic salads in a Midwest winter  
Time to plant for fall and winter harvests!  
Plant now for winter and spring  
Fall and winter greens  
Plant a last minute edible fall/winter garden
Winter growth slow down