Pots & Troughs For Aging Knees

Where soil is tired and compacted, troughs are a boon

When The Third Time Is Not The Charm

I recently visited a little garden that was both bare and overgrown, with scrupulously raked beds and struggling shrubs and trees leaning to catch a bit of sun. The gardeners had tried to plant all sorts of things, from peonies and ferns to rhododendrons and cherry trees. Unfortunately, few of these were growing well and many had passed on to a better world (hopefully). Two steps into the space, several key issues were apparent: heavy soil, poor drainage, and overzealous grooming. Perhaps because the paths weren’t well defined, every inch of the garden was raked (or perhaps even swept) clean, sometimes exposing tree and shrub roots. This is a common issue with tidy minded people who find the look of fallen leaves unattractive. If that’s the case, adding a light layer of compost will hide the leaves and speed soil healing.

This is especially important in shade gardens, as most shade lovers appreciate open, deep soil. Many do best in soil that’s similar to the duff that develops in forests and wooded areas as leaves and twigs, mosses and lichens meld into a wholesome blend over time. In this little garden, ferns would seem to be a good choice, yet they had all died. Only swamp lovers might thrive in the heavy, wet soil, and even those prefer an open soil over tight, anaerobic clay. Such soil doesn’t drain well even where it’s sloping. The only things that really heal sour, acid clay soils are air and humus. To open them up, sprinkle some granulated humid acid, then top it off with a few inches of compost each year. Some people prefer to use a mixture of compost and finely shredded wood chips or tree “waste” (but not bark!), and that’s also effective over time. Lowering paths between beds helps with drainage and air penetration too, especially if the paths are then filled with wood chips or crushed gravel. (Avoid pea gravel, which tends to migrate and is treacherous underfoot.)

Alas, Poor Rhodie

One gardener looked sadly down at a bunch of bare sticks and said that they really wanted a rhododendron there but this was the third one they’d tried in that spot. As a rule, when the same plant fails in a certain spot three times, it’s time for a new idea. Though the area was sloped, drainage was impeded by the heaviness of the soil, which was also scraped bare and full of roots from many large trees nearby. It’s admittedly hard to give up our garden dreams, especially when we have a very clear mental image of how we want the garden to look and what we want where. When our heart is set on having a plant that isn’t able to live where we want to see it, it’s far easier to add a generously sized pot for that plant than to try to amend very challenging soil. This is particularly true when there’s a sense of urgency and we want to see the garden of our dreams NOW, not in five or ten years.

Patience is definitely the gardeners’ friend, yet as we age, we may indeed develop a sense of urgency about projects in the garden and elsewhere. Some of us get great satisfaction from growing trees from seed, knowing that at best, only our grandchildren (or somebody’s grandchildren) will see them in magnificent maturity. For others, such long term projects are exercises in frustration. They’re not wrong, yet it’s also possible to take a middle path and adopt something from each strategy. For a quick boost, plant annuals, perennials, grasses and shrubs and enjoy them immediately and (hopefully) for many years to come. For the long term, plant trees and larger shrubs, placing them with care (!!!) so they have room to develop their full natural form and size without touching the house or outbuildings. Also, before planting an ultimately large tree or shrub, look up. If the area you chose is overhung by branches of large nearby trees, think again. Those big branches will only get larger and longer over time, shading and stressing anything planted below them. Also, roots follow limbs, filling the soil under the branches, further stressing other plants.

Where Space Is Limited, Try Troughs

In small gardens surrounded by large trees, pots and troughs are often a better choice than planting into challenging soil. Where drainage is poor, they’re especially helpful, as you can provide your plants with good, well drained soil that allows air to reach the roots. This isn’t about leaving plant roots exposed, but heavy soils are often anaerobic and plant roots need air as well as water and nutrients. Open, well drained soils let in enough air to suit the roots and promote good drainage while retaining enough moisture to keep plants contented. A clutter of small pots will be harder to care for than a few larger ones, needing to be watered several times a day in hot, dry weather and requiting fresh soil each year. Larger pots with a volume of 2-3 cubic feet can be refreshed with humid acid and compost each year and retain moisture longer than bitty ones.

Troughs and stock tanks can hold up to a cubic yard of soil, offer a generous enough depth of soil for roots to support compact shrubs and small trees. Always drill extra drainage holes in the bottom of such containers and remove any drainage plugs. These are usually on the side of large troughs and here’s a tip: I battled to remove one by prying it out, only to discover that the plugs are threaded and unscrew quite easily. Who knew? Prop each large container on bricks or cement blocks to allow air circulation, which helps keep soil healthy. If you grow annual crops, stir up the soil with a small garden fork each spring and refresh soil with compost before replanting. In my tiny garden, some troughs hold annual edibles and others host perennial pollinator pleasers such as long blooming pineapple sage (Salvia elegans) and Agastache, aka hummingbird mint, both of which are indeed hummingbird magnets as well as bee pleasers. The troughs take up relatively little space and are delightfully easy to tend, especially for those who find bending, stooping and kneeling increasingly difficult. Anything that makes gardening easier as we age is a definitely boon. Onward, right?