Freeze Baby!

And just like that, it’s time to prepare your garden for Winter! We skipped right over frost warnings and went straight to a freeze warning for tonight. Oh Minnesota, somehow your sweet Summer song always lulls me into forgetting about Winter lurking around the corner. It seems like yesterday I was sweating away, swatting mosquitoes, harvesting the abundance from my gardens. So how on earth is there a freeze warning for tomorrow!?!

Since I’m aware the fast change always catches me off guard, I asked friend and local Master Gardener, Brianna Godhe, to give us her take on getting our vegetable gardens ready for the inevitable. The Ramsey County Master Gardeners have been a great asset to our local gardening community, recently attending a Harvest Party, available for Q&A.

Take it away Brianna-

Tucking the Vegetable Garden into Bed

As the days get shorter and the evenings get cooler, it’s time to think about preparing your vegetable garden for winter. It’s hard to think about ice and snow in September when the sun is still warm but you want to be ready. Our average first frost date– that is, the date when we can expect a hard frost which will kill the tender and warm-season crops in your garden – for St. Paul, MN is October 9. It can happen anytime from the end of September to the end of October. It’s a hard truth: once the State Fair ends, our gardening days are numbered. 

To be ready, here are some general guidelines for preparing the garden for winter. These will put you in the best position for starting again when the snow melts next spring.

Steps to Prepare Your Garden for Winter

Step 1: Pick the remaining vegetables

Many of the common vegetable garden plants like peppers, tomatoes, green beans, and eggplant will die when exposed to the first frost. If there’s a frost warning for your area, consider that your last chance to harvest those more delicate vegetables.

Other crops are a little more tolerant of cool weather and, if you have the opportunity, it’s worthwhile to leave them in the garden a little longer. The cool temperatures encourage them to convert some of their starches to sugars as a kind of natural anti-freeze, while also making them taste a little sweeter. These include cole crops (broccoli, Brussels sprouts, cabbages and kale), and most root vegetables (beets, carrots, and parsnips). Just make sure to remove them before the ground freezes. If you haven’t harvested them before that happens, usually in early November, they will be stuck in the ground forever. Don’t let it happen to you.

Step 2: Remove all remaining vegetation

Since just about all of our vegetables are annuals, there is no point to keeping that plant material in the garden over winter; they aren’t going to re-sprout in the spring. If your plants were healthy, you can put the remaining plant material (i.e. the leaves, stems, vines, unripe fruit and roots) in your home compost. Be sure to cut it into small pieces so it breaks down faster.

If the plant material was diseased with any fungi, bacteria, or viruses, you will need to either bury it 6-12 inches to breakdown the pathogens, burn it with approval from your city, or dispose of it with a city yard waste program. (Remember: you can’t put plant debris in the trash!) This is important because many of those pathogens can survive the cold of winter and will infect new plants next year if not treated properly. For the same reason, when you are day-dreaming about the garden for next season, plan to rotate your crops, or place them in a new spot in your garden, which further protects them from lingering disease issues.

Step 3: Test your soil

If you have the chance, your local Extension program can analyze a sample of the soil from your gardens and make recommendations about how to make it more productive next year. These tests aren’t limited to the vegetable garden. You can submit samples from anywhere in your yard to get more information about those areas and what you can do to improve them. If you get the results back before the ground freezes, you can even treat the area by adding compost or specific amendments in the fall for a faster start in the spring. For gardeners in Minnesota the University of Minnesota’s Soil Testing Lab is a great resource.

Step 4: Insulate your garden beds

Without the plants growing on top, your garden soil is exposed to the elements the full force of winter. The soil will expand and contract with the freeze/thaw cycles, which can wreak havoc on the beneficial microbial life in the top foot of your gardens. To preserve your soil, the best thing to do is insulate it. You can do this using cover crops, like winter rye planted in September/October, or you can simply rake fallen leaves on top to act as a blanket. If you mulch your leaves beforehand, you can leave them on the garden bed and they will compost in-place, adding fertilizer to your garden without needing to do anything more. In the spring, you’ll cut down the cover crops and remove any leaves to help the soil warm up to a temperature that helps seeds germinate. (If you leave them covered, your garden beds will stay frozen much longer. You don’t want that.) **See Photo

 Step 5: Clean your garden tools

Once your beds are cleared and protected, take a look at your gardening tools. This includes your shovels, shears, rakes, hoes, stakes, trellises, buckets, pots and any seed-starting trays. After removing any dirt and plant debris, clean the surfaces with a 1:9 solution of bleach and water. (For example, 1 cup bleach and 9 cups water)

This is a good practice generally but it’s especially important if your garden tools had any encounters with fungi, molds, bacteria or viruses during the growing season. Using a bleach solution prevents the pathogens from infecting new plants the next time the tools are used. Make sure the cleaned tools are completely dry and properly oiled so they won’t rust.

Make sure to disconnect your hose and watering equipment and empty it of water so it doesn’t burst. If you have bird baths, watering cans, or rain barrels, make sure they are empty and store them upside down to prevent any lingering moisture from expanding and cracking the frames.

That’s it. Your vegetable gardening season is complete for the year. Great job!

Brianna Gohde – Ramsey County Master Gardener

University of Minnesota Extension Master Gardener volunteers use research-based horticultural knowledge to inspire change and promote healthy people, healthy landscapes, and a healthy planet.

Extending the Season

Are you like me and try to eek out those few extra days of growth in your vegetable gardens? If you want to know the numbers I’ve added this chart from Farmer’s Almanac.  It shows the lowest temps at which different vegetables can survive. If you want to try and extend the season a little longer like trying row covers or other garden tactics, here’s my Season Extension Article to get you started.

And here’s another article with lots of solid  ideas on how to Garden into Winter. by Jessica at:

Feeling Prepared for Winter

Thanks so much Brianna! I know I need reminders (especially about taking care of my tools!)

I’d also like to add that while cleaning out our annual vegetable gardens for the Winter, it’s a great idea to leave your perennials. These seed heads and stems give the birds and insects food and homes over our harsh winters.

Having a plan always makes transitions easier. I hope this helps you and your gardens get set  for the next season!

Dig In!
Michelle