Cut and divide perennials

For the ambitious hobby gardener, cutting and dividing your perennials is one of the most time-consuming tasks in your garden. However, if they are done correctly, the hobby gardener will be rewarded with a colorful sea of ​​flowers in the garden. If you follow just a few rules, you can extend the life of the plants through targeted and sensible cutting and dividing measures. The cut also improves the willingness to bloom and the division creates new plants that decorate the garden in a different place.

remount cut

Experts speak of remounting pruning when the plant is radically pruned back after flowering. Cut back immediately after flowering to a height of 5 to max. 10 cm above the ground. However, not all perennial plants tolerate a replacement cut. Below is a small selection of plants that tolerate a replacement cut well:

• lady's mantle (Alchemilla epipsila)
• mountain knapweed (Centaurea montana)
• gold basket (Chrysogonum virginianum)
• Larkspur (delphinium)
• lavender (Lavandula angustif.)
• Meadow knotweed (Polygonum bistorta)
• horned violet (Viola cornuta)

post bloom pruning

When cutting after flowering, the perennial is cut back just as radically after flowering. As a rule, the cut is made a hand's breadth above the ground. However, in contrast to the remounting cut, no renewed blossoming is to be expected with the post-blossoming cut. Nevertheless, post-flowering pruning has some advantages. On the one hand, healthy new growth is promoted, thereby increasing the lifespan of the plant. On the other hand, hobby gardeners maintain the authenticity of the variety by cutting after flowering and prevent self-sowing. Ultimately, the shape of the pruning prevents wilting and fungal attack. Among other things, the following can tolerate post-flowering pruning:

• lady's mantle (Alchemilla mollis)
• Indian nettle (Monarda)
• Jacob's Ladder (Polemonium caeruleum)
• joint flower (Physostegia virginiana)
• coneflower (Rudbekia laciniata)

early fall pruning

The early autumn pruning takes place around the end of September. To do this, the foliage of the perennial is cut back close to the ground. This pruning produces overwintering buds and rosettes. Early fall pruning makes sense for the following plants:

• ox tongue (Anchusa azurea)
• dyer's chamomile (Anthemis tinctora)
• girl's eye (Coreopsis grandiflora)
• blanket flower (Gaillardia)
• splendor candle (Gaura lindheimeri)

pre-flowering pruning

The pre-blossom cut is called "pinching" in technical jargon. This takes place in early summer, before the flower buds have formed. For this purpose, the shoot tips of the perennial are shortened by about ten to 15 cm. The purpose of pruning is for the plants to become bushy, branch well, and set up more buds. This cut keeps the perennial plant a little smaller, but it is much more stable. In addition, the flowering time can be postponed somewhat. Here are some examples of pre-bloom pruning:

• tall asters (Aster novi-belgii)
• chrysanthemum (Dendranthema grandiflora)
• sun bride (Helenium)
• Phlox, Tall Phlox (Phlox paniculata)
• high coneflower (Rudbekia laciniata)

Cutting out the flowers

Cutting out the flowers describes the regular removal of flower stalks and flowers that have already faded. By cleaning out the flower formation is promoted, the flowering period is extended and self-seeding is prevented. However, only the faded part may be cut away. Examples of some plants where trimming will really increase flowering time:

• ox tongue (Anchusa azurea)
• summer aster (Aster frikartii)
• Corydalis (Corydalis cava)
• sunflower (Helianthus microcephalus)
• daylily (Hemerocallis)

Cutting out the seeds

Among the perennial species, there are many that still have attractive foliage after flowering, but self-sow uncontrollably. So it makes perfect sense to cut out most of the seed heads before the seeds ripen. As a result, the varieties do not split up and self-sowing is prevented. With onion plants, cutting out the seed pods can encourage onion regeneration. The following perennial plants are suitable for cutting out:

• Zierbärenklau (Acanthus longifolius)
• chickweed (Cerastium tomentosum)
• steppe candle (Eremurus robustus)
• bush mallow (Lavatera thuringiaca)
• lily (Lilium)
• burnet (Sanguisorba minor)

post-winter pruning

In contrast to the pre-flowering pruning, it makes more sense for some perennials to only cut back in spring to maintain them. Mainly because they form a framework in the garden as a visual eye-catcher in winter and are therefore better protected against frost. In addition, they offer insects a hiding place and their seeds serve as a food source for numerous bird species. The following plants can be cut close to the ground immediately after winter:

• goats beard (aruncus)
• Calamint (calamintha)
• snake head (Chelone obliquata)
• ragwort (Ligularia)
• sedum (Sedum telephium)

Properly divide perennials

If perennials are left in one place for too long, they can become 'stale' or 'age'. The ability to bloom then often decreases or they no longer grow as quickly and become bare in the middle of the nest. Some types of perennials age by becoming dry and brown on the inside or tilting outwards due to a lack of stability. Then it is high time to divide the perennials and rejuvenate them. In this way they become more vital and thrive. Tip: When dividing, there are often small offshoots that are no longer used in the garden. Placed in planters, these offshoots will beautify the balcony or terrace next year. Provided they have strong roots and at least one shoot tip.

Optimum time

First and foremost, the timing depends on the plant. Countless perennials like the peony feel at home undivided in the same spot for several years. For others, the opportunity to share is auspicious every three to six years. Perennials are generally divided in spring or autumn. A distinction must be made here between summer perennials and autumn-flowering plants, which can usually be divided in spring, and spring-flowering plants, which tolerate division well in autumn. Instructions for sharing:

• only share parts from the edge area of ​​the plant
• Carefully dig out root stock with root soil with the digging fork
• divide dense root balls with a spade
• Sections should have at least two shoot buds
• Pluck loose roots with your hands into fist-sized pieces
• Remove weeds from the soil, treat with compost or organic fertilizer and plant again
• Water the perennial well

When dividing, it is important that any dried and diseased root parts are removed before planting. Examples of perennials that can be divided after three to five years:

• columbine (aquilegia)
• gods flower (Dodecatheon meadia)
• carpet chamomile (Matricaria caucasica)
• catnip (Nepeta graspii)

After six to ten years, for example, the following perennials should be divided:

• cat paw (Antennaria dioica)
• Larkspur (delphinium)
• macaw (Liatris spicata)
• joint flower (Physostegia virginiana)

The following perennials can be divided and transplanted after ten to 15 years:

• pearl basket (Anaphalis)
• globe thistle (Echinops)
• sun eye (Heliopsis scabra)
• Chinese reed (Miscanthus sinensis)

Among the innumerable types of perennials there are also long-lived perennials that can do without division, but often want to be reduced due to their spread. These include, among other things:

• Autumn Anemone (Anemone hupehensis)
• hazel root (Asarum europaeum)
• deadnettle (Lamium maculatum)
• peony (Paeonia)

frequently asked Questions

Worth knowing about perennial pruning shortly

Most perennials need to be cut and divided. They are usually divided when they get too big and have spread too much. In addition, some perennials have to be divided regularly in order to maintain and improve their ability to flower. They are cut for various reasons. You can do a pre-bloom pruning, a bloom pruning, a post-bloom pruning, a rejuvenation pruning, and a back pruning.

types of cuts

• Pre-flowering pruning is a targeted pruning of the shoots before the flowers begin. All shoots are shortened by about half. Pinching off the tips of the shoots promotes branching and the beginning of the flowers. The perennials remain lower, are more compact and very stable. However, the flowering time is delayed by up to 20 days. The right time for this cut is from the end of June to the beginning of July. Pruning is worthwhile for summer and autumn flowering plants bedding perennials How sun eye, Sunbride, Autumn Aster and Phlox.
• Flower pruning is done to prolong the flowering period or to encourage the perennial to flower a second time. With many perennials, the flowering time can be extended if you regularly cut out the withered flowers. In this way, new flowers are continuously formed. This cut is ideal for purple coneflowers, blanket flower, Perennial Sunflower, Suneye, Summer Marguerite and Goldstorm Coneflower.
• The cut for a second flower is called a replacement cut. It is a total pruning after the first flowering. The perennial is cut back to a hand's breadth above the ground. A mineral fertilizer and sufficient watering promote renewed sprouting. This cut is ideal for gardendelphinium, fine beam aster, summer daisy, gardenlupine, Summer Sage, Spiderwort, Ladder to Heaven and Globeflower.
• Post flowering pruning is done to prevent self-seeding. This preserves the authenticity of the variety. The seedlings of many varieties vary and are often worthless. But they often displace the mother plant. So you cut off the withered inflorescences before they reach seed maturity. This cut is particularly useful for sunflowers, phlox, goldenrod and spiderwort.
• The taper pruning ensures a more compact growth. Since some perennials quickly become unsightly after flowering, fall apart or become similarly unsightly, they are cut back completely after flowering. They will sprout again after just a few days. The fresh green leaves look much better. The clumps remain compact. The appearance is fundamentally improved, even if there is no second flowering. This cut is useful for comfrey, lungwort, veillady's mantle, magnificentcranesbill and many geranium species.

cutting time

• The pruning in autumn or early spring serves to form new shoots.
• In winter, perennials that are less stable and easily seeded should be cut back by November at the latest.
• If the perennials are stable and adorned with attractive infructescences, they are allowed to stand over the winter.

When perennials are bare in the middle of the clump, their vigor slows down and there are no more flowers, it is time to divide them and rejuvenate them. You dig up the clumps and divide them into small pieces. These can be used again, if possible not in the same place. Only strong and vigorous sections are used. The growing parts are on the edge of the eyrie. The sections should have at least two to three buds.

• The best time to divide is during the dormant period between autumn and early spring.
• Grasses are generally divided in spring. Peonies are only divided in autumn.

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