Earthbox · Garden · Raised Beds

Frost Protection For Gardens

We have mild winters here but it can get cold enough overnight that some of our plants need protection. Sometimes it can seem like a hassle but the payoff is that we can grow food year round. With a little planning, we can eat from our gardens every day of the year. Here is a look back at last year and the changes that I made for this year.

Last year we installed hoop houses made of PVC pipes over two of the raised beds. I draped and secured painter’s plastic over the hoops. I didn’t want to invest in actual greenhouse plastic at that time. To be honest, timing played a role. I didn’t have time to order it by the time I needed it. I’m not all that good at planning ahead even when I know that a plan needs to be made. Painter’s plastic is easy to find locally but I was not impressed with it. It didn’t provide the frost protection I expected. I ended up adding Christmas lights and a frost blanket directly over the plants. I also used a work light that I hung from one of the hoops. It seemed like a lot of work for very little benefit although it did do the job of protecting my garden from frost a least a little.

A few months ago I started to think about what I might try this year when a garden friend shared with me her theory about small hoop houses. She’s known several other gardeners who have done the same as I did with similar disappointing results. Her theory is that the plastic (even the good greenhouse plastic) used on small hoop houses actually makes the interior colder. It has the opposite effect! I’d love to look more into this theory since there is so much information online about using plastic on hoop houses in small residential gardens. But for this year, I’m taking my friend’s theory and running with it.

Last year was the first time I used a thermometer with a remote sensor. I leave the sensor under the frost protection in the winter and I’m able to see the temperature from the base station inside the house. It records the high and low outside temperature so I can see how cold it was over night. There are many different options for these and I bought the cheap one. So when the hoop house wasn’t performing as well as I had hoped, I blamed the thermometer. I ended up driving myself NUTS (and wasting a good two or three weeks) comparing it to several different types of thermometers and rotating them under and on top of the frost protection.

Aside from trying to figure out if the remote sensor thermometer was working, I was also trying to figure out how much frost protection was actually being supplied by each of the elements that I was using. It was a lot of work and note taking that I don’t think I’m going to bother with this year even though I’m changing things up a bit. However, that process taught me that our backyard is consistently about 5-7 degrees colder than what is reported for my city. That is a big difference in terms of frost protection!

This year I’m only using frost blankets, burlap and Christmas lights.

 

Frost protection - Christmas lights under frost blanket
Frost protection – Christmas lights under frost blanket

Frost Blankets

Last year I tried three different brands of frost blankets that are available locally. The one that supplied the best protection was Jobe’s. It was also the only one with a label that stated how many degrees of protection it offers. This is an important bit of information that I was surprised to find lacking on other brands. One of the brands that I tried made no difference at all. None! There are many different types and thicknesses. For our area, the Jobe’s Frost Blanket that I’ve found at local nurseries has 6-8 degrees of protection. Other areas should carry what is needed locally. Of course, there are also many options online. My one critique of Jobe’s is that, according to the label, it shouldn’t be left on for more than 48 hours. This may be a problem if you’re planning to head out of town during a cold period.

 

Frost protection - burlap hung over trellis. Only one side is up. I drape another piece on the other side of the trellis.
Frost protection – burlap hung over trellis. Only one side is up. I drape another piece on the other side of the trellis.

Burlap

Burlap is my answer to that problem. In my research I haven’t found a limit for how long burlap can be left covering plants. One winter I left it on for almost two weeks without any issues. The problem with burlap is that it can be heavy. You’ll want to prop it up above tender plants. Stakes and small tomato cages come in handy. I primarily use burlap around the trellises in my Earthboxes. Even though the burlap is heavy, I’ve had it torn off a trellis by strong winds. In the process, it also severely damaged the peas. I secure it with clamps now. Even though the burlap can be left on for a long time, I still remove it every day. We don’t need day time frost protection where we live, thank goodness!

 

Frost protection - Christmas lights wrapped around trellis with burlap
Frost protection – Christmas lights wrapped around trellis with burlap

 

Frost protection - clamp holding burlap to trellis
Frost protection – clamp holding burlap to trellis

Clamps

I should mention that you’ll need clamps to hold the blankets and burlap in place especially on windy nights. We have raised beds so I need clamps that can open wide enough to secure the blanket to the wood box. You can also use clothespins to wrap the blanket around an area and secure the blanket to itself. Last year I used garden pins to secure the blankets to the soil but those pins can rip the blanket easily. With gentle handling the blankets can last for several years. You can also use rocks and bricks to keep them in place.

 

Frost protection - clamp holding burlap to trellis
Frost protection – clamp holding burlap to trellis

 

Frost protection - clamp holding frost blanket to raised bed frame
Frost protection – clamp holding frost blanket to raised bed frame

 

Frost protection - clamp securing frost blanket to hoop house PVC pipe.
Frost protection – clamp securing frost blanket to hoop house PVC pipe.

 

Frost protection - garden pin securing frost blanket
Frost protection – garden pin securing frost blanket

 

Frost protection - frost blanket tucked between trellis and raised bed frame
Frost protection – frost blanket tucked between trellis and raised bed frame

 

Christmas Lights

This is my favorite part of frost protection although I fear it may become extinct in the near future. You need the regular old fashioned Christmas lights. The newer LED ones do not emit heat so make sure you buy the right ones. Stock up on them right after Christmas. I bought a bunch of mini lights last year for $1 but right now (before Christmas) I’ve seen them for around $5. I weave the strands around the raised beds and let them lay right on the mulch and under the frost blanket. They don’t get that hot so you don’t have to worry about burning your plants. You’ll need to get them close to the plants because they don’t give off a ton of heat but another degree or three can make a difference. A frost blanket will help keep that heat inside.  There are other types of outdoor lights that can be used especially if you need more heat but for us in Southern Nevada Christmas lights work well…plus they’re fun decorations!

Mulch

It’s not just for frost protection but I thought I’d mention it anyway. Mulch helps regulate the soil temperature. Pile up the mulch around cold sensitive plants.

Thermometer

A remote sensor thermometer is a must! All my experiments last year trying to figure out if my cheap thermometer works showed that it actually does. There are many fancier models with a lot more bells and whistles but for now this works fine. The reason this is a must is that it helped me figure out that one of the frost blankets I tried didn’t work at all and that our backyard is significantly colder than the “official” temperature for our town. Without using a thermometer, I would have never figured out those important bits of information!

Floating Row Covers

I’ve never used them because I haven’t found them locally. I seem to have a real problem with planning ahead to order them online. I never remember in time! Anyway, this is another option that is very similar to frost blankets. They come in different thicknesses for different levels of protection. They can be left on for much longer than the frost blankets I use because they let in more sunlight, air and water. However, the more frost protection you need means the less of those elements it will let in.  It’s still a good idea to lift them off the plants frequently if not everyday.  They can also be used to cover a hoop house.

More Blankets

Aside from store bought frost blankets and row covers, you can also use your old sheets and light blankets from around your house. I would probably use old ones that you don’t mind ruining as they can get pretty dirty. Since they’re not made specifically for the garden, take them off each day to allow the sun and air to better reach the plants.

Cold Frames

This doesn’t really apply to our climate as these aren’t really necessary but they are definitely a handy tool to look into for those living in climates with harsher winters.

There are many options for protecting plants during the winter. Luckily, our winters are mild so we don’t have to dig too deep into our bag of tricks for our garden plants to not only survive but also thrive.

Advertisements

3 thoughts on “Frost Protection For Gardens

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s