The media is buzzing with stories about ‘warmer than usual winter days’. Just this past week, Salt Lake City reached temperatures in the mid 60’s! This is certainly nice for spending time outside, but what is the effect of long stretches of warm winter temperatures on garden plants and what can you do about it? Here are five tips for adjusting your garden tasks to help your garden plants cozy up to the idea of unseasonably warm winter days; and you can even do them in your shorts and flip flops if you so choose!
- Fruit trees – for many, this is your primary concern, big beautiful juicy peaches in the summer, right? You may notice that the buds on your trees are starting to swell and wonder, is this a bad thing? Well the answer is, yes and no. Yes, because when buds of early developing tree fruits like apricots, peaches, and sweet cherries, expand and develop earlier than usual, they become more vulnerable to damage from frost. Hence the ‘no’ part, if the temperatures stay mild, the flower buds will be OK. Certain fruit trees, like stone fruits – cherries, peaches, and apricots, typically set more flower buds than needed so a few buds lost to frost can still yield in a good summer crop. However, if temperatures dip too low, like the teens or worse, this can mean trouble. The problem with warm weather in February is that we still have a lot of winter days to go until we are out of the woods. Here is a tip, watch temperature lows, and if temperatures dip below 30°F, cover vulnerable trees with a large blanket or tarp. This will not save your crop if temperatures dip too low, like the teens, but it might help save your potential fruit load through a cold winter night or two. The USU Extension fact sheet ‘Critical Temperatures for Frost Damage on Fruit Trees’ is a great resource for predicting bud kill at various temperature lows.
- Fruit trees – because we care so much about enjoying tree ripened fruit, let’s stay on the topic of fruit trees for one more tip. Typically we break out our pruning tools when flower buds begin to swell and snip away. However, for years like 2015, it may be hard to know how much damage has been done to flower buds. Here is a tip, wait until the flowers emerge and look for evidence of frost damage (brown or black tissue) in the flower center. If a large percentage of flower buds are damaged, make sure to preserve (don’t prune off) those that do not show evidence of damage. This is why it makes sense to prune a little later (at bloom) than usual for early developing tree fruit like apricots, peaches, and sweet cherries on strange weather years.
- Vegetables – suppress your burning desire to plant your vegetable garden early. Warm weather in February does not necessarily mean temperatures will stay mild through spring. Remember, gardeners plan vegetable garden planting times around the average last spring frost and warm winter weeks have no bearing on spring frost dates. Be patient and start your seeds inside instead – spring will come eventually.
- Planting – perhaps you weren’t able to find time in the fall to transplant a berry bush or purchase a new fruit tree, can you do it now during warm winter weather. It’s not the best time because it is impossible to predict what the weather will do in the coming weeks. It is best to plant plants in unfrozen ground so they can immediately begin to grow roots into their new home. Even though the ground is not frozen this week, who knows about the next, so it is a little bit of a gamble? That being said, it is not a bad time because woody plants (trees and shrubs with wood) are in a dormant state. So it’s up to you, if you want to take the risk, go for it! However, make sure you purchase plants that are adapted to local temperatures (have been kept outside at a local nursery) as opposed to purchasing plants that have been shipped in from warmer climates. And as always, water newly planted or transplanted trees and shrubs into the soil immediately.
- Watch for Pests – one good thing about cold winter temperatures is that they can suppress certain populations of overwintering garden insect pests. Some insect pests, like aphids, are forced to overwinter as eggs in freezing temperatures. All is not lost though if winter temperatures stay mild, an unpredicted spring freeze can catch emerging pests off guard and suppress early populations. If you are interested in learning more, check out this fascinating Utah Pests article ‘How Winter Weather Affects Insect Activity’ by USU Extension entomologist Ricardo Ramirez.
Lastly, remember, no matter how hot it gets out there, stay cool! You can’t change the weather so you might as well enjoy it!