Growing Concerns 146: Continuous color perennials, lawn aeration

Yearning for Continuous Bloom in the Landscape

Every spring I buy so many plants, my family says I'm a gardening junkie. You would think that after years of this, I'd have enough perennial flowers, shrubs and trees, but I don't. There are still times in summer and fall when my yard looks dull and colorless. Any suggestions? - T.B. -

Two things we can suggest. First, regarding plants to bloom at all seasons, read right on, below. Second, for a broader and often more effective strategy for continuous color, click through to Color vs. Bloom.

Many of us are guilty of plant binges, especially when we go out in search of flower color. Step back and observe the action at a garden center in May. You'll see people acting like sharks in a feeding frenzy, snatching anything with a flower on it. Some of those sharks, sadly, will be us!

In this frenzy, garden center managers are the ultimate enablers. They showcase spring bloomers and start other plants early in the greenhouse to bring them into flower weeks ahead of the natural schedule. So our yards are glorious in May and June but dull later because they reflect our spring shopping sprees.

Our defense is to make a list before we go and try to stick to it. We identify weeks or months when color is needed, and use plant encyclopedias to find what blooms then.

Over the years and with readers' help we've developed an extensive list with about 500 bulbs, perennials, shrubs, vines and trees described by color, height and preferred site, with all the plants sorted by their time of peak bloom. We use the list to quickly find some hardy candidates to plug color gaps.

We published the list back in the hard copy days as the chapter Quest for Color in a book that's out of print except as an e-book on our CD Asking About Asters. We've wished to format the list and post it here on the website but it's a big project that will need the support of a very generous Sponsor, or multiple Sponsors, or a lot of people buying copies of our CD.

Right: Formatting, posting and illlustrating Quest for Color here on GardenAtoZ.com involves at least a week's work, and probably more since we never simply transfer data from archives to website. (We have the habit of updating and expanding everything we post, as well as customizing each of our talks as we present it. This habit does slow our posting here, but it furthers one of our prime personal goals -- to keep on growing.)

You can buy a copy of the CD for $20. You can Sponsor us and mention in your pledge that you'd like to support Quest for Color. Either way supports this work for less than the cost of three more not-quite-right perennials.

Continuous Bloom vs. Continuous Color

Creating continuous color in a garden or landscape is not only a matter of what you plant but how you tend it, how you capitalize on plant forms, textures and foliage colors, and also how you manage the interplay between plants and non-plant elements in the garden. This is one of our favorite topics so we've written about it many times and also summarized and illustrated it in:
            • Design a perennial bed
            • Designing Your Gardens and Landscape, our book
            • Expert Afield on
                  - Best fall bloom
                  - Fall color landscape
            • Perennials lists
            • Renovating and redesigning, in Growing Concerns 582
            • Small spot, big color
            • The presentation or workshop, Continuous Color in the Landscape
                  - Schedule this presentation for your group
                  - Download the presentation outline for all the key points and plant lists

Add air to see a lawn grow deep and rich

Tell me about aeration for a lawn. How, why and when? Is it a do-it-yourself project? - P.Z. -

Core aeration counteracts effects of heavy traffic or compacted soil, strengthens grass by encouraging deeper, healthier roots and can eliminates thatch build-up if the lawn has that problem.

A core aerator rolls across lawn, piercing it with metal tubes. Each tube extracts a core of soil and drops it on the lawn, much as would happen if you "walked" a pair of cookie cutters across a sheet of dough, lifting the cutters and shaking them at each step to dislodge their contents. There would be holes in the dough and blobs of material lying near each gap.

Cores deposited by an aerator are deep and narrow, three to four inches long and 3/4 inch in diameter. After an aerator rolls by, it's easy to imagine a squadron of strictly disciplined, well-fed geese have been there. The cores seem to be droppings in straight lines at six inch intervals. (Photos in Help your lawn.)

Aerating builds thousands of tiny compost pits in your lawn. The cores it deposits gradually dry, crumble, and are scattered by mowing or raking. Microorganisms in that soil break down any dead plant material they encounter, just as they would in a compost pile. This eliminates thatch -- dead grass blades that mat down and refuse to decompose on some sites.

Aerator-made holes act first as channels for air and water, then as little compost pits. Air and water stream in, invigorating roots at greater depth than before. Lawn clips and crumbs from cores fall in to make loose, rich compost that stimulates root growth.

Some turf managers top-dress after aerating, spreading a thin layer of topsoil and fertilizer or compost. This speeds up and increases root improvement.

A full-service lawn care company can aerate for you, or do it yourself. The equipment is standard at tool rental shops. Expect to pay $100 or so to use a tractor attachment or walk-behind core aerator for a day. You may be able to rent by the hour or you might split a day's rental between a few neighbors so you can all aerate. The machines aerate up to 20,000 square feet of lawn an hour -- a lawn 100 feet wide and 200 feet long.

Don't expect aeration to follow in your tracks if you wear golf shoes. Solid spikes make holes by compressing soil . That's exactly what aeration is trying to remedy! Also, shoes don't deposit cores on the surface to act as top-dressing.

Aerate any time grass is actively growing. Early in spring or fall can be ideal because the lawn will be just entering a long cool growing period. Many experts aerate annually in fall, since fewer weed seeds can seize that opportunity to sprout and become established in the compost.

Yet the turf tenders at botanical gardens, golf courses and public parks aerate whenever and however often their lawns need that care. The lawns at one estate we know are aerated four or five times a year, after each of the most heavily attended annual events.

It's smart to reserve an aerator in advance if you want to rent it on a spring or fall weekend when the demand is high.

Originally published 5/4/96