The spiree are shrubs with beautiful flowers, capable of embellishing any garden. They tend to flower in the spring and summer months, although some varieties will also produce beautiful leaves during the fall. One of the key elements to take care of spirea is to prune it when necessary.
Steps
Method 1 of 4: Learn the Fundamentals of Pruning
Step 1. Find out why it is necessary to prune spirea
There are several reasons for pruning spirea, which include:
- Take care of the height and spread of the shrub in order for it to maintain a beautiful shape.
- Remove diseased, damaged branches and dead parts.
- Encourage a second flowering.
- Eliminate suckers to prevent the plant from overgrowing.
Step 2. Prepare to take out some suckers
Some varieties of spirea produce suckers, shoots that sprout from the roots. They are capable of producing new plants completely independent from the main one. The production of suckers is one of the ways in which spirea reproduces.
Pluck or cut the suckers if you don't want spirea to spread in your garden. You will learn how to proceed in the next section
Step 3. Know when to prune your spirea variety
Dead, diseased and broken branches must be removed at any time of the year, while healthy ones must be pruned at the right time. If you own a Japanese spirea or pink spirea, prune it in the spring before the flowering season begins. Other spirea varieties need to be pruned once flowering has finished.
- For spirea varieties that bloom in spring, pruning usually takes place towards the end of spring.
- For spirea varieties that bloom in summer, pruning is usually done in late summer or autumn.
Step 4. Learn why pruning after the flowering period can help the plant grow
Pruning after flowering gives the plant more time to develop new branches before the flowering season starts again the following year.
It is not that bad, if you are late in pruning it. You do not risk damaging the plant, but the flowering will be less abundant the following year
Method 2 of 4: Prune the Spirea
Step 1. Don't be afraid to radically cut the plant
If you are afraid of pruning it too much, don't worry. Spirea can cope with good pruning and it is difficult to mistreat it. It will grow back even after a rather radical cut.
Newly planted shrubs do not need to be over pruned. You may want to trim them slightly to keep their shape during the first year
Step 2. Try to leave at least five shoots on each stem
Try to shorten each stem so that it holds about five shoots. Use a pair of sharp garden or pruning shears. Remove any dead, diseased, or decaying branches; at the same time, get rid of even the weakest looking ones or the stems that look too thin.
Any thin or weak, dead, diseased or damaged stems should be cut down to the base
Step 3. Prune the plant
To keep the bush from becoming too thick, remove a few branches in the center of the plant to thin out the shrub. It means cutting the branches that make the bush too thick.
Step 4. Remove unwanted suckers
When you prune the spirea, it would also be useful to eliminate any suckers, or the sprouts that sprout directly from the roots. This will prevent the plant from developing through these growths. Therefore:
Remove the suckers as close to the root base as possible. Scrape off some dirt around the root if necessary. Try tearing them instead of cutting them
Step 5. Prune the old, woody parts of the spirea
If the spirea is old, thick and woody, you can regenerate it with a radical pruning. One third of all old woody stems should be shortened to the ground. If you do this for three years in a row, the plant will reinvigorate itself by developing new branches.
Step 6. Take care of the spirea after pruning it
After pruning, water the plant, fertilize it, and renew the mulch. A slow release fertilizer is best. A blood, fish oil, and bone fertilizer is a great choice, but you can also buy a more commercial type. Sprinkle it under the spirea and with the rake gently embed it into the soil.
You should also add about 2 inches of compost, leaf soil, or well-rotted manure around the spirea to act as protection
Method 3 of 4: Divide the Spirea Shrubs
Step 1. Consider dividing the spirea
In addition to pruning, you may also want to consider dividing it. After a few years, plants such as spirea can become a little dull; by dividing them at the root, you have the possibility to regenerate them and remove the older parts.
In this way, you will also get more plants
Step 2. Divide the spirea in late fall when the plant is dormant
A great time to divide is when the sky is covered with clouds, as the roots are in danger of drying out in the heat of the sun once they are exposed to the air.
Water the plant well the day before you plan to divide it
Step 3. Divide the spirea
The day after watering it, dig it up, removing as much soil as you can from the roots, without damaging them. For this purpose it would be useful to have a hose for watering. To divide the plant:
- Use a tool, such as a spade or saw, and cut the root collar in four.
- Each piece should have a healthy section of the root and some fairly sturdy stems.
Step 4. Prune the roots after dividing them
Remove any old root sections at the end and discard any damaged or parts of the plant that look rotten. At the same time, cut off the parts of the plant that protrude from the ground, removing any damaged or dead stems and some of the older, thicker, woody ones.
Transplant the root sections and in the spring, when the plant starts growing again, you will have new, vigorous stems
Method 4 of 4: Caring for Spirea Over Time
Step 1. Mulch around the spirea
A good mulch in spring is healthy for spirea. Therefore, spread a layer of about 5 cm of well-decomposed compost or manure all over the area under the branches of the bush.
It will help keep the soil moist during the warmer months, prevent weeds from growing, and later protect the roots from the cold as temperatures drop
Step 2. Water the spirea more often during the warmer months
During the summer it will be very grateful when you water it in particularly hot or dry periods. Keep in mind that once established, plants do not need frequent watering, except in the warm months.
Step 3. Protect the spirea from aphids
This is not a very problematic plant, but it could be attacked by aphids from time to time. Look for curled leaves, as these indicate that these pests are beginning to spread.
Generally, a good sprinkling of the garden hose is enough to get rid of the aphids. You can also use a commercial pesticide against aphids
Step 4. Watch out for fire blight
See if the plant has blackened and curled tips of the stems - this is a symptom of fire blight. Try to radically prune the affected areas and then burn as much as you cut.
Advice
- The different varieties of the spirea grow in height between 60 cm and 3 m. Be very careful when pruning taller ones - using sharp blades on a ladder can be risky.
- If you water the spirea excessively or if the soil does not drain well, there is a risk that the leaves will turn yellow and die.
