Rejuvenate faved perennials that have lost their vigor

The blooming of your favorite perennials has lost its luster? Cut back yellowed leaves and divide stumps to renew their vigor, propagate them and give them away.

Read also:

• Propagating perennials, the right technique
• Growing dahlia the right way
• How to grow carnation and also garden pink
• Peony growing and care
• Growing iris for nice blooming

Create your own dahlias

To boost flower-bearing for your dahlia until fall, remove wilted flowers regularly (deadheading). You can also let several buds mature so you can collect seeds that can be sowed in the following spring.

• This will give you new unique varieties with simple flowers, that you can name after yourself or a loved one! And, if you’re particularly proud, submit them as candidates in garden fairs and contests… if all goes well, you might even patent the variety!

Cut bleeding heart back at the beginning of August so that a second remarkable wave of flowers can bloom at the end of summer.

• Cut all stems with a hedge trimmer down to 4 inches (10 cm) above soil level and keep the ground cool if the plant is in direct sunlight.

Dividing your irises and peonies

Four years after planting, your bunches of iris have grown and must be divided!

• Unearth rhizomes and choose the strongest ones, whittling them apart with a sickle.
• Weed and break up the soil, and plant them in a circle, placing each rhizome 12 to 16 inches (30 to 40 cm) apart.
• Water to let the soil settle down.
• Roots will start developing even before winter starts.

Peony is harder to unearth. Water abundantly the day before if the soil is too dry.

• Use a spading fork to lift plants up.
• With a well-sharpened blade, slice the stumps. Ensure that four or five nice roots and three or four buds remain on each piece.
• Spade and till a well-drained plot, lightening the soil up 16 inches (40 cm) deep with sand and fertilizing it with organic fertilizer (dried blood or old manure).
• Place your peonies in an open and sunlit space, since they are easily overwhelmed by shrubs or other perennials.

Rejuvenate your carnations

Generally, perennial carnation loses vigor rather quickly, and its blooming starts weakening as soon as three years after planting.

Dwarf garden pink must be divided at the end of the blooming season, which is from May to July.

• Remove stumps from the earth using a small pitchfork slid under the roots.
• Grasp them firmly in both hands and split them apart in several bunches, with leaves and roots on each.
• Replant at 10 inch (25 cm) intervals.

M.-C. H. with minor edits by Gaspard Lorthiois