Winter Planting Guide
Late winter planting can be tricky to manage. Here are some tips on winter planting best practices and timelines.
February 25, 2022
Timing planting is one of a landscaper’s trickier tasks. This will depend on where your customers live, what kinds of plants are desired, and the soil composition.
While there is not a horticultural reason to plant early, one benefit to winter planting is that contractors can get ahead of peak labor demands by planting trees before the spring season.
Winter Planting Background
Trees can be planted in winter if the ground is workable and not frozen. Container trees (grown in a plastic container) and ball and burlap trees (product that has been harvested and burlapped during the fall digging season) are ideal for this purpose. Planting trees in the winter is similar to nurseries or growing yards “mulching in” to protect against the harsh elements.
Note that soil doesn’t freeze right as the temperature becomes 32˚F. Soil freezes once temperatures stay consistently below freezing all day, for multiple days in a row. Warmth is stored in the soil (especially deeper into the ground) long after there is freezing weather.
Nearly every species can be planted in late winter, assuming that species is appropriate for the USDA zone in which your customers live. Some examples include palms, maples, elms, and oaks according to their zones.
All irrigation systems should be turned off after being winterized. However, make sure you provide water to the trees; newly planted trees will still need water for about a month after planting.
- Newly planted trees still need to be watered in the winter, even when dormant. Water deeply at time of planting and then at least once a week for at least one month.
- Add a layer of mulch to protect your newly planted tree. This should be at least two to three inches thick.
- Temperatures below 20˚F can cause problems, especially for newly planted trees. If your area is predicted to get unusually low temperatures, don’t panic. When temperatures are predicted to get well below 30˚F, deeply watering the tree and allowing water to freeze around the roots will maintain the temperature around the roots at 32˚F.
Be Aware of Potential Issues
One major hiccup in winter planting is that some grower and nursery yards might not have easy access to the material. While this will depend on your geographical location, the colder states may winterize their operation with mulched and covered growing beds. Ensure your nursery has what you need available before beginning your job.
Another common problem is frozen ground. If frozen, it’s challenging to get a good mixture of soil in the planting hole between the native soil and the root ball. There are potential issues if a late winter storm rolls through. These include ground refreezing, splitting bark, and being unable to properly protect trunks from extreme cold conditions. Use the tips above to combat these issues.
Know the Plants and Your Zone
Most dormant trees store energy to produce blooms in the spring. If planted correctly, roots will grow when dormant to establish the tree. This means trees can be planted in fall and winter for beautiful spring blooms. Be sure to plant fruit trees in fall however, as these types of trees need time for the roots to establish in order to produce more fruit in the spring. If you plant in the spring, trees need to spend time and energy on root production as well as flowering and may go through a shock period, which means they will likely bloom less than a tree planted in fall or winter.
Deciduous trees are a decent choice to plant in the winter. Avoid planting evergreens during this time unless you live in a climate where the ground does not freeze. Because the foliage of evergreen trees never drops and stays green, they need to be able to continue to take up moisture, so the roots must get established before the ground freezes.
It’s very important to know the different grow zones. Here is a breakdown:
Zones 1 and 2 - These zones are too cold to successfully plant in winter due to average minimum temperatures of -60˚F to -50˚F.
Zones 3, 4, 5, and 6 - These are still cold, but to a lesser degree than zones 1 and 2. You can plant a cold, hardy tree in these zones without it being harmful, but you cannot plant in the middle of winter here. The ground will be frozen, you won’t be able to dig the plant in, and watering would be very challenging.
Zone 7 - Labeled as an “in-between” growing zone, it’s safe to plant dormant trees here, assuming the ground is workable. Be sure to watch the forecast- do not plant in this zone if weather predictions call for a prolonged deep freeze within 10 days.
Zone 8 - Mostly a warm zone, this zone is safe to plant as the ground may not freeze at all. If it does freeze, it will likely be a short period of time. Ensure the soil is workable before beginning to plant.
Zones 9, 10, and 11 - These are the subtropical zones. Winter is one of the best times to plant here, as these zones rarely reach freezing temperatures. The ground doesn’t freeze. These are the only regions where landscapers can plant evergreen trees during the winter season.
Zones 12 and 13 - Extremely warm, tropical environment; plants here need to be suited for intense heat. Winter is a good time to plant here also.
SiteOne Can Help
Visit your local SiteOne nursery or use our Nursery Direct program to get the plants you need for the job. Associates are happy to assist in answering questions and helping plan projects. For more nursery education, see other nursery articles within the Learn section of SiteOne.com.