Mulch perennials and bulbs after the soil freezes

While waiting for winter and the soil to freeze, start thinking about mulching both perennial and bulb flower beds.

Although snow is the best winter protection for perennials, we can’t always depend on adequate snowfall to form sufficient insulation. Protective cover can help protect plants from extreme cold. More importantly, it prevents fluctuating temperatures and early spring warmups from bringing plants out of dormancy when they may be vulnerable to damage by cold temperatures.

Alternating freezing and thawing that can happen in both early winter and spring can cause plants to lift or heave out of the soil, which can destroy plant roots.

When to apply mulch

For spring flowering bulbs, applying mulch after the soil has begun to freeze will prevent them from emerging too early in the spring when they may be damaged by late freezes.

Apply protective mulch as soon as the soil begins to freeze, or any time after that. Mulch can be applied on top of the snow, and the snow will increase the insulating value of the mulch.

It is tempting to apply the cover mulch when we are cleaning up the gardens in the fall, but it is very important not to apply it to perennials before the soil begins to freeze, as this may encourage growth beneath the mulch that will ultimately weaken the plants.

What type of mulch to use

Useful and effective mulches for perennials and bulbs include five or six inches of whole or shredded leaves, partially decomposed compost, ground corn stalks, and straw.

Although wood chips and shredded bark are excellent mulches, they are better used for covering the soil between plants where it can be left undisturbed throughout the year.

Remove the mulch as it thaws in early spring to avoid crown rot and other fungus problems, but keep a cover handy in case of a late spring freeze.