Tuesday, May 25, 2010

Contain Yourself!

About this time of year, you begin to see lots of advertisements and information about container gardening. Most of them focus on pots and baskets full of brightly colored annuals. Some cities, such as Victoria, BC and Edmonds, WA are renowned for baskets hanging off of every lamppost and burgeoning beds on every street corner. There is no doubt that annuals can make a good show and many are long blooming. However, I’d like to dig a little deeper, so to speak, and consider other interesting and imaginative ways to use containers.

Containers are extremely versatile. Even the smallest porch or patio can accommodate a pot filled with lovely plants. A striking container with just one well chosen plant can make an impression at your entry or next to a pathway or as a focal point in the garden. On the other extreme, you can plant several containers with large scale plants and create a living screen for your patio or deck. Uses of container gardens are unlimited. You can grow vegetables, roseIlex crenata 'Golden Gem' bushes or Japanese maples in your pots. On the Microsoft campus in Redmond you can see massive containers, each holding a Japanese maple or a Katsura tree. On my patio, I have pots with a sturdy central tree or  shrub that remains and I change the rest of the plants with the seasons-or when the mood strikes me.

Containers can be plastic, terracotta, wooden or glazed pottery. Some of my favorite containers were designed and displayed by Wells Medina Nursery in standard metal trashcans. I’ve seen flowers  planted in old siwinter silvernks, wheelbarrows and discarded boots. The Mukilteo Community Garden has an old iron bed frame planted with sedums in a quilt inspired pattern. Gardeners say, “If it holds soil, it’s a container.”Just be sure that whatever you pick to display your plants has plenty of holes in the bottom for drainage. You can make holes in hard surfaced containers with an electric drill and an appropriate bit.

I’d like to opine for a few minutes about soil, because soil is crucial in every type of gardening. An old adage states if you have $10 to spend on your garden, spend $9 of it on soil. This seems backwards, but the truth is, even the healthiest, strongest plant will suffer or even die in poor soil. All plants require water and nutrients, and air is necessary for the roots to absorb these properly. So, drainage is crucial; waterlogged soil will drown a plant.

Since containers generally only drain through the holes in the bottom, they require different soil than the average garden variety. Even a good garden soil is too heavy for containers. Good soil for containers is lightweight, drains well yet holds moisture. In other words, we want the particles that make up the soil to retain moisture but we want the mix to drain well and ensure the roots get plenty of air.

Some gardeners use soil to make their own potting mix which is part mineral and part organic. Mineral ingredients could be vermiculite, pumice or perlite-all of which contribute lightness and good drainage. Organic ingredients might be peat or compost; these contribute moisture retention. These are all added to the soil in varying proportions. When you are starting out, it is a good idea to use a commercial soilless mix; it will save you time and eliminate a lot of variables such as soil borne disease and getting the proportions right. These soilless mixes are frequently called potting soil which creates some confusion. Some are specific to the type of plant, such as cactus, African violet or seed starting mixes. For outdoor containers, you will want a general mix. Some have additives such as fertilizer or moisture retaining polymers. Read the labels, try different types and see what works best for you.

Large containers can be extremely heavy when they are full of moist soil and plants. If you are using a very large pot, you can put packing peanuts in the bottom below the level you expect the roots to fill. Make sure that you use polystyrene peanuts; biodegradable packing peanuts made of starch will dissolve in water. Cover that with a piece of landscape fabric which is water permeable. Then fill the container with our soil till they are about 4/5 full, and water it to settle it in. You will add more soil after you have placed your plants. When all is done, it is very important to have at least 2” between the top of the mix and the rim of the pot to make watering easier.columnar-apple-trees

If, on the other hand, you have a relatively  small or narrow pot with a taller plant or bushier plant, you may want to make the bottom of the pot heavier to prevent it from toppling. If your arrangement threatens to be top-heavy, use gravel in the bottom of your pot instead.

My next post will be on selecting plants for your containers. So pick out your containers and get your potting mix and drainage material ready to go!

1 comment:

  1. You make it sound so easy and so much fun! I think I will have to try it.

    ReplyDelete