Frost Protection 101

We are so fortunate to live in an area where we can grow vegetables year round with minimal effort. Protecting your vegetables from frost allows you to extend the harvest well into winter, and for those who are diligent in their efforts, carry it right on through to next spring.

Green Meadows
Early November 2013!

We typically see two types of frost in the garden:

1. Advective frost - is the condition where a sudden cold front sweeps into the area with gusty winds and immense cloud cover.  The layer of cold air is so thick and dense; it can actually reach as much as a mile high. Rarely will we see a first frost event under these conditions, but it can happen. 
2. Radiation frost - is the type of frost event most common to our area and the one we mainly think of.  The nights have little to no wind, skies are clear, and the stars are simply beautiful for gazing.  

Both types of frosts can be very damaging to plant cells and tissues.

Frost protection works as an insulator to protect plants from the harmful effects of the event.  The protection is valuable to the veggie gardener in two different ways.

1. It protects plants from the effects of frost on their leaf surfaces that frequently leads to damage within the cell and tissue structures.  This is most often damage that is beyond repair, resulting in permanent injury at growth points, wilting, and potential death to the vegetable.
2. The protection also works as an insulator to hold on to your ground temperatures by creating a micro-climate within your bed.  Keeping the ground temperatures up allows your plants to continue their growth and production cycles for an extended period.  All plants will eventually reach a point of hibernation and overwinter.  However, the more growth that the plant has, the greater harvest a gardener can achieve through this period of rest.

Green Meadows Healthy Garden Tips for Success During Frost Events:

1. Harvest early - warm season vegetables are the most sensitive to frost events and the time has come to go ahead and harvest what you have left.  The texture and flavor in these crops will dramatically fall off with an extended cold period even if you cover.
2. Know the cold tolerance of your plants - all cool weather vegetables have different tolerances to frost and cold weather.  As an example, many of the brassica's are at their peak flavor when you allow frost to reach them, however, if you have any peas producing; it is wise to harvest. While the pea plants are very tolerant to cold and mild frost events, the pods are not.  Cell structures can burst within the pod itself and ruin the texture and flavor.  Vicki and I have learned this lesson the hard way several times. 
3. Irrigate before the frost event - irrigating before the frost event arrives builds much needed moisture into the soil.  Moist soil will hold the heat as much as four times greater than dry soil according to several published university studies.  One study even shows that the increased air temperature, right above the soil level, was still five degrees warmer than dry soil at 6:00 am the next morning when watered the evening prior.  This can be the difference between having plants with damage and having plants without.  For those that are covering, it is important to water late the day of the event, but still allow the leaves to dry before erecting your frost protection.
4. Cover your plants - using frost blankets can provide several degrees of additional warmth to plants.  While the covers can be laid directly on the plants, this method provides the least amount of protection and the greatest risk of still receiving injury from the cold.  Any material can really be used to cover your plants, although you will find your best protection comes from woven fabrics. Plastics should be avoided if at all possible as they tend to do more harm than good unless using those specifically geared for vegetable growing.  Remember to vent your structures in order to keep plants from overheating when the temperatures start to rise above 45 - 50 degrees. 
5. Irrigate during the event - this is actually a trick that Mike would use now and then if he were unable to get over and cover in the evening.  Rinsing the frost off early in the morning before it has a chance to penetrate the plant's cell structures is a method that some tend to use.  This can work for very light frosts in the 32-degree range if done right before sunrise.  Rinsing the plants with water during the event keeps their internal temperatures from freezing and prevents the cold damage to cell structure and tissues.  However, with that being said, frosts occurring at lower temperatures would need several applications throughout the night or a system of overhead irrigation that you would see among professional growers.        

Mr. Wesley checking his cover!

Regardless of what method you choose for covering your plants, not all frost protection is created equal and much depends on how you have conditioned your plants to accept the cold when it arrives.  A nice way to gauge what you are purchasing is to look at the temperature rating of the product.  While those with only a two to four degree rating have a place in the early fall and late spring, they are not heavy enough to carry plants through the entire winter unless using many multiple layers.  Vicki and I both use a combination of very light covers purchased from Pike's and the garden quilts available through Gardener's Supply.  Between the two products, we can pretty much handle anything the weather seems to throw at us.

If you need any help preparing for the cold spell, please don't hesitate to ask.  I am attaching this link as a very basic article from Botanical Interests that shows the frost tolerance of many vegetables.  It gives you a brief overview of what can tolerate what temperature alongside some other very important factors.

https://botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables - link to the frost tolerance of vegetables from Botanical Interests.

Happy Gardening,

Denise, Beds 25 & 29

Squirrels and Frost go hand in hand

Our favorite pest, i.e. those dratted squirrels, are becoming more active. They hadn't done much digging in the garden up in September. But now that it is October, I have noticed quite a few holes in the middle of beautiful patches of brand new seedlings.

Squirrel Deterrent......sort of

I've been watching the squirrels sauntering through the garden, looking for the perfect place to carefully dig a hole and place the treasured nut they were holding in their mouth.  Even though it is a nuisance to move the netting every time I work in my bed, I'm glad I went ahead did it preventatively.  At least this way I don't come to the garden and get instantly aggravated at what was destroyed nor do I have to keep replanting!

The chilly temperatures Sunday morning jump started my thought processes - when is the 1st frost. Or the question really should be, when is the 1st frost usually (but not always).

The answer - October 31st. Though it can be sooner than the 31st and as late as Nov 15th. A light frost doesn't cause as much damage as a hard freeze. This year I'm probably going to just let nature take its course but I will fight the good fight for awhile with the lettuce since I just got it going.

If you plan to use a frost cover now is the time to think about it, acquire your supplies and construct your frame.  And while you are at it, do a trial run to see if you have everything you need to anchor the cover! There is nothing worse than putting it together and then getting a call or email that your frost cover has come untethered and is flapping in the wind or the whole thing has collapsed.

If you are interested in protecting your bed from the dratted squirrels or your plants from frost and freezes, here are links to posts I've done in the past.

http://greenmeadowscommunitygarden.blogspot.com/2012/11/simplest-frost-blanketrow-cover-to-use.html

http://greenmeadowscommunitygarden.blogspot.com/2012/12/bed-41-vickis-frost-cover-method.html

http://greenmeadowscommunitygarden.blogspot.com/2012/11/denises-frost-cover-tall-sturdy-any.html

Good luck in the squirrel wars!

Vicki
Bed 41 

First Freeze/Frost of the Year

Freeze Warning! Freeze Warning!

If you have baby plants, just put out tender transplants, or even not so tender plants....this post is for YOU!  Time to start checking the weather every day for low temperatures.

Be sure and water well Friday to give your plants as much help as you can before the cold weather. Actually, give them a good drink on Wednesday as well since the low is supposed to be 37 on Thursday morning. The more open and exposed a garden area is, the higher chance of frost. In fact, frost typically occurs when the temperature reaches 34 or 35 degrees at Green Meadows.

Saturday morning the low is predicted to be 29 degrees. Your peppers and tomatoes will definitely freeze to a pulp with no protection so be sure and harvest what you can even if they are green so they will ripen slowly in the house. Lettuce won't hold up well without protection. Neither will your sugar/snow peas which definitely need frost protection. You can try to cover the tomatoes/peppers but it depends on how long it is cold as to whether it will work.

If you have brand new seedlings you definitely need to cover and fix the cover so it doesn't blow off and expose the tender growth. If those tender plants are exposed they will get frost bite or even get killed.

This picture shows several different kind of frost covers that were used Fall of 2012

Below are links to several blog posts explaining how to use different methods of creating/using frost covers.

Vicki's Frost Cover Method

Denise Frost Cover Method

Simplest Type of Frost Cover 

Frost Tolerance of Vegetables

Hi Everyone,

What an amazing idea to use a blog to communicate among the gardeners!  Kudos to those who have put this together for us.  

I thought it might be nice to post something regarding the frost tolerance of vegetables since the cool weather to come is inevitable.  I found this link on the website of Botanical Interests and it has some excellent guidelines of what your vegetables can withstand.  Please remember that these are only guidelines though, and if in doubt, you may want to cover.   http://www.botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables  

And on a related note........

One of the most important things I have learned over the years is to realize that not all frost blankets are created equal.  Let's just say I learned that lesson the hard way! Wind chill is a factor.  It is wise to look for those that have a temperature rating listed on them.  As an example, protects plants down to 24 degrees or provides 4 to 6 degrees of frost protection.  This provides you with an idea of whether one blanket is enough or do you need an extra layer.  The blankets do work incredibly well and if diligent in your covering, many vegetables will continue to produce all winter.

Low or high tunnels are extremely easy to construct and if you look at Vicki's (Bed 41) or mine (Bed 29) it should get some ideas flowing.  I can't wait to see what we all come up with!  

Has anyone found some good pricing on frost blankets?  Pikes did have them on sale two weeks ago for $6.99.