Winter Protection

Protection of primulas in their winter dormancy period is not a simple, one solution works best type of problem. What works in England or the lower 48 states may not work in Alaska. The method of protection used should be specifically suited to the site exposure, terrain and typical weather conditions as well as to what primula are being grown.

One of the best winter protections of primula goes back to the preparation of the site. Most primula resent standing water, especially in winter. Avoid this problem by not planting in low spots, by mounding beds, and by using welldraining soil.

South-facing sites, especially up against a building or fence, are the most likely to be difficult for primula in winter. Areas under evergreen trees are also less than ideal. Snow cover may be diminished here, causing the plants to be exposed to extreme temperature fluctuations.

Ideally, primula grown in northern climates should have good snow cover throughout the winter to protect them from extremely cold temperatures, temperature fluctuations, and drying winter winds. If snow cover is reliable, no extra protection of most primula is needed. Anyone who has lived in Southcentral Alaska for more than a few years knows that, weatherwise, anything can happen, and snow cover may be a long time in coming.

Spruce boughs laid over primulas offer some of the best supplemental protection possible. This is especially true for winter wet climates like Southeast Alaska and scree covered rock gardens. With boughs you don’t have to worry about debris packing down and rotting around the plant crowns or messing up the aesthetics of a rock garden. You will have needles to garden around in the spring but those are the tradeoffs.

Some gardeners in Southeast Alaska use elevated panes of glass to protect some alpine types of primulas from too much winter wet on their foliage. Each gardener decides to what extent they will go to protect the plants they love!

The next best winter protection is a 4”-6” layer of deciduous leaves such as birch. This simulates the leaf and debris cover many primula would have in the wild. This method works especially well in regions where winter temperatures stay reliably cold. This would not, however, be appropriate in wet Southeast Alaska winters where the leaves would become a suffocating mat. In the spring, the mulch should be “fluffed up” by hand as soon as the snow melts and left in place for a few more weeks. The plants have a chance to get some air but are still protected from growing too soon while temperatures are still quite cold. When temperatures have grown milder, remove all the leaves, preferably with a leaf blower, to avoid damage to plants. If the leaves are not removed, the soil stays cool and pests find more places to hide while they secretly munch your treasured plants. A springtime layer of compost or other feeding amendments can be added after the garden has been cleaned up.

Avoid straw if at all possible as the cleanup in the spring is a huge pain. Voles are more likely to find shelter with your primula under a blanket of straw than with the other protections mentioned.

Each gardener must experiment with what winter protection works for them, with the plants they grow, and the site conditions they experience. The successes and failures we find along the way are part of the great adventure of gardening.