Steele: Time for early summer cleanup in the perennial garden

Plants flourished in the unusually wet spring. Now we’re in for a sudden blast of hot, weather.

Volunteers work together to do the early summer clean-up at the unH2O Xeriscape Demonstration Gardens aquatic centre in the Okanagan Mission.

Volunteers work together to do the early summer clean-up at the unH2O Xeriscape Demonstration Gardens aquatic centre in the Okanagan Mission.

With the unusually wet spring, plants have flourished and bloomed abundantly.

Now it looks like we’re in for a sudden blast of hot, summer weather.

The abrupt change will be hard on plants and flowers will fade quickly.

Now is the time I like to do a midseason, major garden clean-up.

Then there will just be some dead-heading and weeding a few times until fall clean-up after frost.

Here are some tips on early summer care for your perennials.

If your soil is wet, and anything other than sand, try to minimize stepping on it to avoid compaction.

Early spring blooming evergreen plants such as phlox, aubretia (rock cress), alyssum, and iberis (perennial candytuft) can be cut back by up to one half to encourage fresh new compact growth.

Cutting them later removes next year’s flower buds.

All compact early bloomers such as armeria (thrift) and dianthus ‘Tiny Rubies’ can have the dead flowers sheared off down to the foliage.

Larger plants whose foliage becomes messy after bloom, such as oriental poppies and geranium ‘Johnson’s blue,’ can be cut back to the new growth.

Deadhead German iris. These tough, drought-tolerant plants can be divided almost anytime.

After dividing, cut back foliage to one half and leave the top of the rhizome exposed to the air.

Deadhead peonies down into the foliage.

Deadhead anything that tends to self-seed as soon as flowers finish—e.g. blue fescue grass and cerastium (snow-in-summer).

To encourage re-blooming, keep dead flowers cut off repeat bloomers such as achillea (yarrow), salvia, rudbeckia, echinacea, coreopsis, and gaillardia.

My two favourite tools for dead-heading are long-bladed shears, for when the whole plant is being cut back, and grape pruners. These are small shears that fit my hand well.

They act like scissors for cutting individual stems but have a spring to open the blades, saving half the hand work.

Years ago my husband gave me a wonderful gift of a tool caddy that fits over a large plastic pail.

In it, I have all my hand tools including my favourite weeding tools: an ergonomic trowel and a dandelion digger.

There’s also room for my water bottle, garden notebook, and camera. Everything is close at hand. As the gardening season evolves, I encourage you to take photos and make notes of any changes you want to make.

It is easier now, to see what will need dividing or moving, than it will be in spring. An excellent reference for getting the maximum performance from your plants is The Well-Tended Perennial Garden by Tracy diSabato-Aust.


If you have a xeriscape garden, I strongly encourage you to enter OXA’s Xeriscape Garden contest. Details are on the events page of the website.

There are two categories for home gardeners and two for professionally designed gardens—one residential and one commercial.

Kelowna Capital News