Maintaining the height and spread of your Spirea Shrub, and to preserve an attractive shape. Removing any diseased or damaged branches and any dead growth. Encouraging a second flowering. Removing suckers and prevent the plant spreading via suckering.

Pinch or prune these off if you don’t want your spirea to spread in your garden. The specifics of how to do this will be covered in the next section.

For varieties of Spirea that bloom in spring, that will usually be late spring. For varieties of Spirea that bloom in summer, that will usually be late summer or fall.

It isn’t a disaster if you delay pruning, and this won’t harm the plant, but your spirea will offer less of a display in the next flowering season.

Newly planted shrubs won’t need pruning as much; you may just give them a bit of a trim to reshape them in their first year.

Any spindly or weak, dead, diseased or damaged stems should be cut right back to the base of the stem.

Remove the sucker by getting as close as possible to the base of the root. Scrape away some soil around the root if necessary. Try to tear off the sucker, rather than cutting it away. [7] X Trustworthy Source Royal Horticultural Society Leading gardening charity in the U. K. providing resources for identifying, growing and caring for flowers and other plants Go to source

You should also add around two inches of compost, leaf mold or well-rotted manure around your spirea to act as a mulch.

You’ll also get more plants by doing this.

Give your plant a good watering the day before you plan to divide it.

Using something like a spade or saw, cut the root crown into quarters. Each piece should have a healthy bit of root and above-ground growth.

Replant the root sections and you’ll have new, vigorous growth when the plant re-emerges in the spring.

This will help retain moisture in the soil over the hotter months, keep the weeds down and, later, protect the roots from the cold as the cooler weather draws in.

A blast of water from the garden hose usually works to dislodge aphids. You can also use a commercial aphid spray.