Promoting a second flowering, removing dead plant parts or stimulating growth: there are many reasons why summer pruning is so important for many garden plants. Which perennials need to be cut in summer and why is it necessary?
Fertilizing, watering, a dry and warm winter quarters: What is important for a perennial so that it gets through the winter healthy? Proper care also includes summer pruning. It fulfills several functions:
- brings the plants into thedesired shape– very important, especially for potted plants, so that they do not tip over in strong winds.
- removes diseased shootsand helps with dry damage.
- promotes a second floweringin late summer or autumn. Certain cranesbill species, lady's mantle, lungwort, several comfrey species and suneye can benefit from a nourishing pruning.
- makes them more resilientand helps with pest infestation.
- prevents self-seeding, in which the plants invest an unnecessary amount of energy. This is atPlants like the columbine, magnificent spire or Jacob's ladder are recommended because they can quickly spread in the garden and crowd out other plants.
- prepares the perennials for thenext falland the cold time ahead.
- Older plants especially need itregular rejuvenation cutsso that they sprout again.
When is the right time for a summer cut?
The right time for a summer cut depends on the flowering. Basically: After the end of the flowering period, you can cut back the perennials in the garden. Provided, however, that the weather cooperates and allows for pruning. Long dry periods, temperatures above 30 degrees and heat weaken the plants so much that they only recover very slowly after cutting. Direct sunlight can also burn the freshly trimmed perennials. That's why it's better to wait before cutting during heat waves.
The best time to do a summer pruning is on a cloudy day. Alternatively, you can do the cutting late in the afternoon, but if it stays warm at night and doesn't rain. This gives the plants enough time to recover.
Which perennials need to be cut in summer?
Basically, most perennials can be trimmed in the summer without any problems. However, since different plants have different care requirements, they are cut differently. Some need a strong pruning, for others thinning is sufficient.
1. Cut lavender in summer
The lavender is cut back in early to mid-July. At this point the first flowering period should already be over. If you notice that the old shoots are becoming woody, you should take the scissors in your hand and shorten the perennial by two thirds. It is important that you only cut back the old shoots - this year's wood does not need any pruning. Never incutting old wood, because the lavender will not sprout again.
Also interesting:Lavender woody: What to do to avoid baldness
2. Lupins are only thinned out
Lupins are typical summer perennials and they are cut immediately after flowering. You should only thin out the plants a little, because the perennials cannot tolerate severe pruning.
3. Remove the dead flowers from lady's mantles
The lady's mantle is gradually cut during the flowering period. The plant is thinned out if necessary and the dead flowers are removed regularly. This prevents the plant from spreading uncontrollably in the garden. Instead of putting an unnecessary amount of energy into seed formation, lady's mantle tirelessly produces flowers until late summer.
4. Only cut off the tips of the sack flower
With the sackflower, only the side shoots without flowers are pinched off or, even better, cut off. Only at the end of September, when the last flower buds wither and fall off, are the plants shortened by a third.
5. Repair pruning of delphiniums
In contrast to the other perennials, the delphinium tolerates and requires vigorous pruning after the end of the flowering period. All shoots are usually shortened to 15 cm. The plant sprouts vigorously almost immediately afterwards and even flowers for the second time before the end of the season.
6. Which perennials need pruning? Indian nettle
The Indian nettle must be cleaned out regularly during the flowering period and the dead flowers must be removed. Pruning is done in a similar way to delphiniums after the end of the flowering period.
7. Promote the second flowering of daisies
Daisies are traditionally cut back in July. Varieties that are not hardy must be cut close to the ground before they move into winter quarters. The outdoor plants are not cut so deeply - they can be shortened by two thirds.
8. Phlox does not need pruning in summer
With phlox, the dead flowers are removed regularly. The plant does not require severe pruning in autumn because the above-ground parts of the plant dry out. In midsummer you can shorten and thin out the phlox a little.
Proper care after cutting supports flower formation
Proper care after summer cutting is crucial - the heavy feeders need extra fertilizer so that they can sprout again. And all plants need to be watered abundantly. Mineral fertilizers strengthen plants and help them recover from pruning.
These plants do not need pruning in summer
By the way, there is also a smaller group of remontant plants that do not need summer pruning. ThisPerennials bloomagain after the end of the first flowering in June. These include, for example, some iris varieties, ornamental sage, noble peony and catnip.
Cutting perennials in summer: the most important things summarized
Most summer perennials require pruning in mid-summer. This generally takes place from mid-July to mid-August, although some plants can also be cut back later. Summer pruning promotes growth, rejuvenates the perennials, helps them to have healthy leaves and supports renewed flowering in August. It also makes them more resilient and can help if the plants are attacked by pests.
Proper care after cutting is also very important. The plants need an extra portion of fertilizer (mineral fertilizer is best) and plenty of water so that they can absorb the nutrients better.
