September is traditionally the month when things start to cool down a little and it’s also the start of the prime time for tree planting. The soil is still warm but night time temperatures, particularly, start to drop and there is some humidity in the air and early morning dews.
We can start to look forward to the first autumn/winter rains. These are good planting conditions, ones in which roots settle in quickly and can take best advantage of every drop of rain. Thus, by next summer, your trees will be quite well established and better able to cope with the baking summer months and be less thirsty. Their roots will have spread out in their own search for moisture and nutrients and they won’t be so demanding on your time and your irrigation system. This has the double advantage of anchoring the tree into the ground so that they won’t get rocked around so much when those fierce autumn gales blow in.
We often talk of ‘established’ plants and, generally, this means one that has had a full year in the ground but the most important start you can give your plants is to plant them well and at the most advantageous time of the year. Of course, pot-grown plants can be slipped into your garden virtually right through the year but their demands on you are going to be greater if you’re planting out of season. This is fine if you’re talking small scale but if you’re planning a major scheme, make it easy on yourself and start now.
You’ve had all those long hot months to think about it – now is the time for action!
Assuming that you’ve made your plans – where to plant and what to plant – I’m just going to run through a few essentials of good planting. These are true of any plant but, in particular, trees because they are going to be around for a lot of years so get them off to the best start.
Firstly, prepare your planting hole. This needs to be two to three times wider than the pot diameter and the same depth. Loosen the sides and base of the hole so that the roots can penetrate. Turn out the tree carefully and study the rootball. Ideally this should be well knitted together but without any roots protruding out of the pot. If your tree is like this, then gently lower it into the hole without any root disturbance. Ocasionally, you’ll see roots that have become potbound and are forced to circle round and round. These need to be gently eased out to break that circular pattern or the tree will never establish properly.
If they are really matted and impossible to separate, prune back these tough roots. This will stimulate new root growth to anchor your tree. Plant the trunk to the original soil depth, check that your tree is upright and put in a sturdy tree stake. Do this now so that you do not damage the roots hammering it in later. Backfill with the original soil which can be enriched with a good quality compost, roughly one part compost to four of garden soil – more than that makes for too light a mix for your tree; it will dry out quickly and not offer sufficient body for rooting.
Firm in well as you backfill, tie the tree to the stake (the importance of a stake is to hold the roots steady – it doesn’t matter if the head of the tree is swaying). Water in very thoroughly and mulch the surrounding area to prevent a hard crust developing where water cannot penetrate and to stop weedgrowth. Weeds, or grass, will take up approximately 50% of the water and nutrients destined for your tree so, initially, keep the area around the trunk clear.
Keep a close eye on newly planted trees, and water long, deep and infrequently in preference to little and often. Your tree roots need to be trained to go down in search of water.
I’m happy to order in for you any plants that I may not have in stock, just call and see me. As of September 4, the nursery will be back on general hours, 10 – 6, Tuesday to Sunday, inclusive.
Lorraine Cavanagh is the author of Mediterranean Garden Plants.
Her plant nursery, Viveros Florena, is on the Algarrobo/Cómpeta Road, at km 15. Look out for the flowerpot lady. Also, catch her weekly shows on OCI radio.