Back to Basics

Are you a new gardener? This is for you; tips for autumn planting success.

Autumn is the best season to plant. Warm soils encourage strong root development, while the cooling air temperatures alleviate plant stress, culminating in the ideal conditions for success. Nevertheless, it can still be fraught with challenges. From undersized seedlings to untimely sowing, insufficient soil preparation and inadequate after care—each misstep jeopardises the endeavour. So, let’s get back to basics to ensure planting success.

Seed-sowing basics

Firstly, consult a ‘What to Sow’ calendar specific to your area. It is important to grow vegetables and flowers that are in season. Winter vegetables, for instance, should besown in late summer and early autumn. Keep in mind these winter crop seeds may require sun protectionin extended warm weather.



Fresh seed is always desirable but larger seeds like beans and peas will often retain viability from one year to the next in are sealed packet.



Sow seeds into a seed-raising mix or sieved quality potting mix. You can also create your own mix by combining equal parts of washed river sand (to remove any fine clay dust), perlite or vermiculite, and sieved mature compost.







Don’t bury your seed, a light dusting of soil mix sieved over them, will suffice. Water seeds in with a gentle rose spray of a weak solution of seaweed to aid germination. Larger seeds like sweet peas can be soaked overnight in water with seaweed added; discard floating seeds.



A sheet of glass over the seed tray or pot keeps the germination environment stable and warm. A heat pad under your seed tray or pot will also aid germination, especially for difficult seeds.



If you are sowing seeds directly into a garden border, make sure your soil surface is devoid of sticks, twigs and stones. Sieving the soil to create a sowing bed depth of 1cm is perfect.



After germination, thin out your seedlings by selecting the strongest plants. Once true leaves appear at around 2-3cm tall, you can add a weak solution of fertiliser to the water.

Seedlings

Seedlings are available in three types of punnets:



1. Mass-sown punnets: require careful separation of individual seedlings before planting.

2. Individual cells with six or eight seedlings per punnet, where you don’t need to disturb any roots, so they are the most successful.

3. Advanced seedlings, one per pot (above).



Costs increase from first to third type but all benefit from watering in with a seaweed solution for root recovery. Novice gardeners will have more success with seedlings, rather than seed, but as your confidence grows you will have a greater choice with seeds.

Trees and shrubs

Garden centres stock a huge range in autumn. Determine the mature height and width of your chosen tree and check that you have enough room for it to grow without overcrowding other plants or structures in your garden.



Before purchasing plants, always inspect to ensure they are free of pests and diseases and not pot bound. Give the pot a gentle squeeze; if there’s ‘give’, this indicates well-developed roots. Conversely, if the pot is hard and resists movement, the plant may be root-bound. Don’t hesitate to ask a staff member to up end the pot and show you the root system for further confirmation.

Planting

Plant your new purchase immediately. Research shows 75 percent of plants left in their pots die at the back door! If you must wait, ensure they are regularly watered.



Good soil preparation and good planting technique is essential if your plant is to survive and grow. Like painting a house, the quality of the result is all in the preparation.



When it comes to planting into heavy clay, rocky or sandy soil, you can cultivate compost and aged cow manure into your planting area. The planting hole should be at least three times the size of your plant pot.



If the pot is 20cm deep, dig your planting hole 30cm deep, but its width should be three times the width of the pot. Lateral roots help anchor your new plant while the slower tap roots are developing. Make sure the level in the garden same depth it was in the pot.







To improve heavy-clay soils, add coarse rivers and, grit or fine horticultural pumice to enhance drainage and soil structure. Avoid digging deep holes that may collect water during heavy rain; instead, consider raising the soil level by creating a mound with a depression at the top. Aim to raise one-quarter of the root ball above the original ground level.



The improved soil will retain moisture, while increased drainage encourages root growth. The depression at the top funnels water directly to the roots, making watering easier and more efficient.



Adding nutrients at planting time does more harm than good. Wait until new growth appears inspring then feed with an organic-based fertiliser.



If a stake is needed, it should be installed at the planting time using a single or triple stake method for initial stability. Remember, the plant must ultimately stand alone and always watch the progress of any ties to avoid damaging the bark.