The popular flowering perennial (also known as delphinium), which has been cultivated in cottage gardens for many centuries, is absolutely hardy even in harsh climates and does not need any special winter protection.
How can I overwinter delphiniums successfully?
In order to overwinter the delphinium successfully, cut back the faded perennials close to the ground in autumn and mulch the root area with humus-rich compost. For potted plants, you can also wrap the pot in case of frost and place it in a protected location.
Pruning delphiniums in autumn
In preparation for winter, cut the spent delphinium back to just above the ground in autumn and then thoroughly mulch the root area with ripe, humus-like compost. This measure should actually be sufficient as a preparatory measure for the winter, because - if it is a perennial variety - the delphinium will sprout again in spring. Only with one- or two-year-old delphinium varieties should you leave the inflorescences standing so that the plant can produce seeds and sow itself again.
Overwintering delphiniums in a pot
Many people prefer to keep delphiniums in pots because the delicate green is popular snail food - and many a snail invasion has ensured that the first tender shoots cannot grow into a stately perennial. Delphiniums in the pot also do not need to be particularly protected, at most you only need to wrap the pot with a warming mat or something similar in very frosty temperatures. Otherwise, a protected location outdoors is sufficient, ideally on a house wall.
Tips & Tricks
The lower varieties Delphinium belladonna are particularly suitable for pots, as they remain significantly smaller than, for example, the Elatum perennials.
