Winter Pruning with Andrew Ristvey – The Garden Thyme Podcast

Although it may be cold and dreary outside, it’s the perfect time to take inventory of your deciduous trees and shrubs to see which plants would benefit the most from pruning. In this month’s episode, we’re sitting down with Extension Specialist in Commercial Horticulture, Dr. Andrew Ristvey. Dr. Ristvey is giving us the ins and outs on winter pruning. 

We also have our: 

  • Bug of the Month  (Winter Stoneflies) at 37:30
  • Garden Tips of the Month at 45:55
  • Native Plant of the Month ( American holly)  at   49:00

Here are some great resources to learn more about pruning: 

 If you have any garden-related questions please email us at  UMEGardenPodcast@gmail.com or look us up on Facebook.

The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Hosts are Mikaela Boley- Senior Agent Associate (Talbot County) for Horticulture, Rachel Rhodes- Agent Associate for Horticulture (Queen Anne’s County), and Emily Zobel-Senior Agent Associate for Agriculture (Dorchester County). Theme Song:  By Jason Inc


Save the date! On March 9, join together with fellow University of Maryland alumni, faculty and staff, students, and volunteers for an extraordinary day of giving back. Make a contribution to Home and Garden Information Center Fund for #GivingDayUMD!

Food gardening between growing seasons

Late fall feels like a bridge between growing seasons. Walking in my garden I love to feel the earth and see the big and small day-to-day changes. I also think about the ups and downs of the 2020 growing season and what I’d like to change in the coming spring. The pandemic and the social, political, and economic turmoil have made me even more certain of the specialness of food gardening spaces. They feed people and connect us to the land and each other. Here are some chores, tips, and thoughts for this time of year:

Prep areas for planting small fruits, like blueberry, gooseberry, and blackberry in early spring. Soil testing is especially important if it’s a new bed or if you are growing blueberry and need to lower the soil pH.  Cover turf and weeds with cardboard, compost, and mulched leaves to create new beds. Research the types and cultivars of small fruit plants you are considering. 

Blueberry leaves turn purple, red, and mahogany in fall.

It’s too late to plant cover crops. Instead, protect exposed soil with a thick layer of tree leaves (preferably mulched or shredded leaves). The mulch can be pulled aside to plant in spring and then re-applied around seedlings and transplants.

Overwinter the growing mix from vegetable containers by emptying the containers on a tarp and removing leaves, roots, and other debris. Store the growing mix outside in heavy-duty black trash bags or trash cans. Re-use the growing mix next season by mixing it 50:50 with fresh soilless growing media and/or compost. Fertilize container plants as needed. 

Garlic- to mulch or not to mulch? Most gardeners and many commercial growers mulch fall-planted garlic with organic mulches, like straw and chopped leaves. Mulch can prevent erosion, smother weeds, and protect young plants from heaving and extreme cold weather. But thick mulches can also slow growth in spring, reduce bulb size, and possibly improve conditions for bulb diseases and pests. There are few published studies comparing mulched and un-mulched garlic. Warming winter temperatures may be making mulch less crucial in warmer areas of Maryland. 

Comment below or email me (jont@umd.edu) about your experiences growing garlic with or without mulch.

Ground ivy and weeds
Ground ivy and other weeds need to be removed in this garlic bed whether or not mulch is to be applied.

Extending the season– leafy greens stop growing around November 15th when day length is less than 10 hours. But higher fall temperatures due to climate change has increased garden productivity- there are more tasty and tender leaves to harvest per square foot of garden space. Kale, spinach, mizuna, beet greens, and other semi-hardy leafy greens can be harvested into December when protected with floating row covers.

A double layer of row cover material accelerates growth in fall and protects plants over the winter. 
Arugula planted in early October is ready for harvest and will re-grow in early spring due to row cover protection.
It’s a great time to clean tools with a wire brush, file the cutting edges of hoes and shovels, and protect wood handles with linseed oil.

Online gardening hacks– one can get lost for hours in the world of “look no further… this is the absolute best way to ______ in your garden.” There are lots of good tips out there if you can ignore the ads and snake oil. I found a site from a small urban grower that extolled the virtues of plastic Ts for trellising plants that I happily used this year.

These 1 ½ in. PVC T-fittings are perfect for setting on top of metal fence posts to accept horizontal supports, like 1 in. electrical conduit. The posts, fittings, and conduit will last many years. 
The fittings (circled in yellow above) just sits on two T-posts 9 ft. apart. The 10 ft. piece of conduit extends over the ends and easily supports cucumber plants.
The fittings (circled in yellow above) just sits on two T-posts 9 ft. apart. The 10 ft. piece of conduit extends over the ends and easily supports cucumber plants.

Reflect on the 2020 growing season: What major problems did you have? What caused them? Can they be prevented next year? Re-think crop choices and plant locations. Did I really need to grow 30 tomato plants and three kinds of eggplant that no one in my house will eat? 

Grow it and give it– plan to share more of your garden with people in need. Contact local food banks and feeding programs this winter to find out how you contribute your fresh produce. 

Keep on learning…

Check out the Home & Garden Information Center website pages on Food Gardening.

By Jon Traunfeld, Extension Specialist. Read more posts by Jon.

Winterizing figs and planting cover crops in a changing climate

Planning, preparation, timing, and flexibility are becoming more important for food gardeners trying to adapt to climate change. For example, some gardeners are planting more late crops and reaping larger and longer harvests of leafy greens in the fall. But severe cold snaps can punctuate long periods of mild weather and injure plants, so being prepared to cover and protect those crops with a floating row cover is still essential.

Similarly, HGIC receives questions each year from gardeners about protecting figs from cold winter weather. If climate change is giving us milder winters do we still need to protect fig plants over the winter? The answer is yes, for most Maryland gardeners, because severe cold snaps will kill aboveground wood even if the average winter temperature is rising. Bending stems as close to horizontal as possible and covering the plant with a tarp or other insulating material is a time-honored technique:

Photo of cinder blocks weighing down fig stems
Two cinder blocks used to weigh down supple one and two year old fig stems. The stems could have been pruned to a more manageable length. Photo credit: Jon Traunfeld

 

Photo of Bags of leaves around Fig Plant
Fig plant is completely surrounded by bags of insulating leaves.
Photo credit: Jon Traunfeld

Planting cover crops in late summer/early fall is a great way to improve and protect soils. Some vegetable gardeners had tomato, pepper, cucumber and other crops going strong into October and asked us if they could plant cover crop seed past the recommended end date of October 1st. Mild conditions and sufficiently high soil and air temperatures allowed for successful late planting well into October. But if you don’t carefully monitor the 7-10 forecasts you can end up wasting time and money.

This cover crop was sown on November 3rd in Central MD and included winter rye, crimson clover, and hairy vetch. The temperature cooled considerably from the previous week, dropping to a record low of 25⁰ on Nov. 9th:

Photo of soil and seeds
A few hairy vetch sprouts are visible but may be killed by freezing temperatures. It’s unlikely that the crimson clover and annual rye seeds will germinate and survive.
Photo credit: Jon Traunfeld

 

The availability of tree leaves in fall gives gardeners some flexibility and another option for soil improvement. Leaves can be spread out over the soil to prevent erosion, improve soil health, and provide a nice mulch for next year’s garden plants. Climate change is forcing us to be better planners and to act quickly when dealing with extreme and unstable weather.

Photo of bags of leaves
Tree leaves are valuable for soil and plant health. Don’t let them leave the neighborhood!
Photo credit: Jon Traunfeld

More fig and cover crop information:

https://extension.umd.edu/resource/growing-figs-maryland
https://extension.umd.edu/hgic/topics/cover-crops-protect-and-improve-your-soil

By Jon Traunfeld, Extension Specialist