Autumn Planting

A Great Time To Go A-Planting

The autumn months can get awfully confusing for us gardeners. The problem lies in our genetic make-up, as us humans tend to think of autumn as a time of gentle decline, a time to wear knitwear and drink soup, for staying in and watching the football or matinees while we get over the shocking loss of summer. Not a time to go gardening.

This is all down to our lack of true plant understanding, but then its not as if our lifestyle in inextricably rooted to a patch of earth that runs as far as you can reach at full stretch. Maybe for that we should be grateful. Our plant friends have to sit it out in the hot dry earth right through the hot summer months; while we can lie in the shade or go and get a cold beer out of the fridge. To plants autumn is an obvious time of plenty. Not to hot to cause stress, yet not cold to stop root growth, and moist as you like. Perfect for root growth and plant establishment.

Autumn And The Root System

The moist warm soil says one thing to the root system. Lets grow; lets catch up in the underground department ready for next spring, and quickly, because once the winter cold sets in its shut down time. So we have the months October and November, and maybe some of December during a mild year here in the south of England. And that’s why autumn is the finest time to plant trees, and shrubs, and the majority of spring flowering bulbs and herbaceous plants as well. Autumn is also an ideal time to sow or lay that lawn as well as sow early spring vegetables and herbs such as coriander and parsley all of whom will actually send roots into the soil at an alarming rate, putting them in an altogether better position come next spring and summer to resist draught and put on rapid new top growth.

Autumn Planting: When, What And How To Plant

Planting is best left until the summer conditions have broken. This usually happens after a few good days of rain and possibly the odd ground frost. If in doubt wait until the soil has become well and truly soaked and the trees have started shedding their leaves, especially if your thinking of planting bear root plants such as native trees and shrubs or deciduous hedging such as Beech.

When planting you get one chance to really improve the root-zone in which your plant will spend the rest of its life. When I say root-zone Im talking about depth multiplied width of the area required for the plant to root into; it’s a cubic thing see as roots will go downward and outward into the third dimension of downwards as well as outwards if you let them. Just a moment’s thought should make it clear - once a plant is positioned and growing away how else can improve the soil beneath and around it? the soil into which it will root and feed from? Now you’re getting it. Best practice is to work on an area 3 to 5 times the size of the pot your using or in the case of bear root 1 to 2 times the area covered by the existing root system.

Digging the hole deep enough is especially important for larger bear root and containerised plants, which are more likely to suffer from poor drainage as they are planted at greater depths, they also happen to be far more expensive and as such an investment well worth providing with a little bit more care! To this end you will need a hole that allows drainage beneath the root system. To allow for this ideally you should dig a hole that big deeper than the root depth and make doubly sure of drainage by forking the bottom of the planting hole and adding compost and maybe some grit just for good measure.

Don’t Try Planting Too Much Too Soon

I realise that I wondering here from the relatively simple realms of ‘how to plant’ but it follows from my last point and it’s just too important. So important in fact that it needs covering again and again. Please don’t start off trying to plant every conceivable type of plant in your garden; always start with what will grow and do well. Take it easy: identify the kind of garden you want and build out from there. Look in your neighbour’s garden, visit local gardens, see what you like, identify it and get to know what it will turn into when it grows up. That is pretty much what this website is about; encouraging gardeners to think a little bit more about their planting decisions. Don’t just wonder into a garden centre and think something looks ‘interesting’. I know a label can give a vague idea what a plant will become but never forget that the label is a sales pitch; they’re trying to sell you that plant, but is it the right plant? Is it suitable? The only way of being sure is to enter the garden centre with a carefully researched planting list.

How To Plant

Having established that we have selected the correct plants for the planting area I will always try and improve the soil in some way prior to planting. This can be achieved by digging and adding. The planting hole is usually 2 to 3 times the size of the potted plant when planting into reasonable quality topsoil. This involves excavating a decent planting pit and piling soil to one side of the pit, where it can be improved by adding a decent amount of well rooted compost and maybe a sprinkle of granular fertilizer such as growmore; ideally you should be aiming for half and half compost and soil mix to back around the plant. I will also usually fork the bottom of the planting hole to help drainage bellow the planting pit, thus reducing possible winter water logging and encouraging the establishing plant to root down that bit deeper. Forking compost or good quality topsoil into the bottom of the planting pit will help further to open up the soil to root penetration as well as improve the quality of soil, allowing roots to access an extra reservoir of soil moisture and nutrients. This is especially useful when planting into shallow topsoil’s, over subsoil or chalk, or, as is often the case with new build gardens – subsoil mixed with building waste such as rubble. In which case you will need to put create a substantial pit to plant into.

Pit Planting

If it is the case that you are planting a tree or a shrub into really dreadful soil such as shallow topsoil over compacted clay, or rubble, then make the planting pit deeper and wider and fork in plenty of compost / topsoil to create a decent sized pocket of good soil that the plant can feed from. You might also need to use a mix of imported compost and topsoil to backfill around the planted shrub. And you might need to create a pit 4 –5 times the size of the potted plant in order to give the chance a fighting chance when it gets to maturity. This is often overlooked as a young plant will flourish in a relatively small pocket of good soil, but how will it fare when it reaches maturity?

Back filling And Staking

When planting any pretty any plant the golden rule is that the back fill should be pulled back around the roots of the plant to a depth just slightly above the existing compost level of the pot. When planting think about just covering the compost without burying the roots to low. The idea is to avoid exposing the existing roots by covering them with a shallow layer of topsoil and compost without drowning the roots by positioning them to deeply. This is important, as plants are very sensitive to planting depth. Once backfill is in place you should firm the new plant either by firming backfill around the plant with your hands (this is usually adequate for flowering plants and ground cover), or for bigger plants such as shrubs tread lightly 3 to 4 times around the plant with the heel of your boot.

If your planting larger shrubs or small trees then you might need to use staking and ties to stop the root system being rocked by winter winds. On smaller plants a light stake positioned at a 45 degree and tied towards the base of the stem should surface. Always avoiding staking into the heart of the root system as that can damage essential roots; that are why an angled stake is good.

Spreading Mulch

This being a shallow protective layer spread – usually to a depth of 7 to 10cm - over the soil to help protect and feed the establishing plant. Ideally a well rooted clean compost such as leaf mould and garden compost or mushroom compost is best for flowering perennial plants, however shrubs and trees are often mulched with bark chip, which is less nutritious but far better at suppressing weeds and locking in soil moisture.

Mulching will provide extra protection to roots of young plants from winter frosts and provide a nutrient boost as they rot away over the following summer season. By applying new compost mulch every few years the soil can be greatly improved in the long term as it rots down to form humus, which is the dark matter content that we associate with decent topsoil. Ideally on perennial beds this should happen every 2 to 4 years.

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