There’s every possibility that you’re reading this week’s Secret Garden rugged up in front of the heater. The first big cold front of the season has swept through, leaving in its wake frosty mornings and doona induced dreams, and according to the bureau, another front is due to sweep through early in the week. It might be May, but have no doubt that winter has arrived.
For me, winter is my busiest time of the year. Besides writing, I run Thistlebrook, a small nursery growing and selling heritage fruit trees. A decent run of cooler weather means that deciduous trees are entering dormancy and I can make a start on tasks like grafting and digging up trees for sale in the form traditionally known as “bare root”.
Unlike containerised plants, which are grown and sold in a pot, bare root plants are literally bare rooted – the roots are free of soil. Some people get worried that buying nude plants in the middle of winter is bad for their health, but they won’t catch a cold, and are actually quite a bit easier to manage. Because there’s no foliage to support, bare root plants are much easier to handle than potted plants. They can be shipped through the mail, or left in moist sawdust until ready to plant out.
Bare root plants are also good deal cheaper, usually by around 50 percent. This reflects the lower costs of production. Another major benefit is that bare root plants grown in well managed soil are very environmentally friendly. There’s no pot to dispose of, they need less water during production and they are a lot lighter during transit, which means fewer greenhouse gas emissions.
Gardeners have developed some dodgy practices as a result of using containerised plants, including the creation of what expert English nurseryman Kevin Croucher calls “luxury planting pits”. These are often deep, poorly drained sumps backfilled with fresh organic matter that can drown or burn the roots of bare root plants. But there’s a worse problem with this practice. The major reason bare root plants fail is because the roots have been allowed to dry out prior to establishment. Fresh organic matter that isn’t fully decomposed will continue to break down after planting, reducing in volume and creating air pockets. Plant roots subsequently dry out and die in the air pockets.
Here’s how I go about planting a bare root tree. I start by analysing the planting site a couple of months ahead of planting time. If the existing soil is really poor, I amend it with compost and whatever else is necessary, perhaps lime or gypsum. If the soil is adequate, with good drainage and a reasonable structure, I simply dig a hole big enough to accommodate the root ball of the new plant, and ensure the fill to go back into the hole is broken up finely. I add no amendments to the soil. The plant is placed into the hole, with the graft union (if there is one) kept at least 10cm above ground level.
If the roots are young and flexible, it can help to make a mound in the bottom of the hole and spread the roots over it, but otherwise I just bung the soil in and give the plant a couple of wiggles to settle soil around the roots, firming it once the hole is filled. The next step is to water, even if the soil is moist. Doing so removes any remaining air pockets, and a dash of seaweed extract in the watering can will aid in root development. A donut of rotted manure can now be spread on the surface of the soil to gently feed the plant as it settles in, the lot is covered with mulch, and by now I’m just about ready for a cup of tea.
Before the jug goes on though, there’s one final question: to stake or not to stake? Generally, the answer is “not”. Small plants rarely need staking at all, and when planting a tree in a windy site, the best option is to get out the secateurs. Take the canopy of the tree back by at least half, always cutting above an outward facing bud. This has the effect of balancing the foliage to the rootball, avoiding top heaviness and allowing the trunk to flex slightly in the wind.
A lot of gardeners are hesitant, but this early pruning is worth it. You’ll end up with a stronger tree with a more extensive root system that shoots away strongly in spring, and will be providing fruit or shade in next to no time.
First published in the Toowoomba Chronicle 15 May, 2010. Photo by Justin Russell – Maples, Davidson Arboretum, Highfields.
