Winterizing a 1st-yr euonymus tree–How?

(Question)

Question is from London ON. We have a fist yr euonymous (grafted) tree. Do we need to cover it or ???? this winter?

(Answer)

Hello, and thanks for your timely question, as our autumn seasonal changes are well underway in Southern Ontario.

Without a reference photo, for discussion sake, let’s say you own one of the two more common ‘standard’ — or grafted tree-forms —  of Euonymus:

  1. Euonymus alatus, commonly known as Burning Bush, known for its fall florescence of red to pink deciduous leaves, and the
  2. Euonymus fortunei ‘Emerald Gaiety’a broad-leafed evergreen with decorative, variegated green-and-white margined leaves. This is the variety with leaves that would be susceptible to the stress of winter weather.
  3. We’ll also assume your euonymus has been planted in the ground, as opposed to a large pot. As a refresher, and for fellow readers, here is the Toronto Master Gardener’s advice on  transplanting and cultural requirements of Euonymus.

If you planted your tree early in the growing season, allowing it to establish a robust grafted root system, followed the transplanting instructions, provided a stabilizing stake for the first year, have continued — right up to now, very important — to water regularly, and mulched around the base (but not close to the trunk), then your tree should be in good shape to winter over. N.B: be sure to not prune now, as pruning encourages new growth that will not be well hardened-off for winter, leaving your plant exposed to potential winter damage.

This now leads us to your question about ‘covering’ your standard Euonymus. Burlap can be used as a wind-break, to reduce or prevent winter exposure injury. Drive in three stakes, the height of your plant, far enough away from the tree so the attached burlap will never come in contact with the branches, even in windy conditions.

If, in fact, your tree is one of the cultivars of Euonymus fortunei, and is situated in an open area, with no protection from adjacent growth or buildings, then you might, in addition, consider applying an anti-desiccant. Desiccation injury occurs when more water is transpired out, or “lost” through plant tissue, more quickly than it’s absorbed up via the roots. Long dry periods of cold and thaw, and winter winds, are the culprit. Anti-desiccant sprays add a protective waxy coating to the leaves of broadleaf evergreens to help slow the process of transpiration. Apply an anti-desiccant when temperatures are around 5-10 degrees C  (40-50 degrees F), when rainfall is not forecast. Foliage needs to be dry when applied, and the spray needs time to dry afterward, so aim for a rain-free period. Whatever brand you choose from the nursery, follow the directions to the ‘T’, and your plant should thank you come springtime!

For further reading:

https://ag.umass.edu/landscape/fact-sheets/protecting-evergreens-in-winter-qa

28/10/21