Beginners guide to propagation

Propagating seeds

While sowing seeds requires extra time and care, it’s something all kinds of gardeners can do, regardless of experience. It’s the best way to grow a massive range of vegetables and herbs such as tomatoes, chillies, and basil, as well as flowers like cosmos, sweet peas and sunflowers. You can propagate seeds either indoors on a windowsill or greenhouse, or outdoors in the garden.

Some seeds must be germinated in a warm, protected environment to sprout, while others can be sown straight into the ground outside depending on the time of year and forecasted weather.

Sowing seeds indoors is the best way to get a head start on the growing season and to protect your seedlings from unpredictable spring weather. Follow the directions on your seed packet to find out the best way to sow your chosen seeds, or follow our guide to sowing seeds indoors as you go.

If you don’t have a greenhouse or enough space inside your home, you can sow seeds outside once the soil has warmed up and all risk of frost has passed. Sowing seeds outside is beneficial as it removes any worry around planting out tender seedlings once established, which always risks damaging them.

It’s best to keep in mind that the sowing seeds method of propagation can take the longest to grow new plants and some plants are harder to propagate from seeds. Even when you’re successful the plants might not grow true to their parent form. However, don’t give up! With time and practice (and a bit of luck!) you’ll manage to propagate healthy plants from seeds exactly how you want them.

Propagating cuttings

Taking a cutting is when a piece of a plant’s leaf, stem, or branch is snipped off and placed into compost or soil to grow a new plant. This is a slightly more advanced method of plant propagation. There are different ways of taking cuttings.

Plants with woody stems, like roses, Azeleas and other shrubs, can be cut at the stem and propagated. You can also use leaves from parent plants to propagate new ones. Depending on the plant species, you can either cut a whole leaf and its small stem and place it in compost or make a small slit in the leaf’s veins and lay the leaf with the slit downwards over the compost. and rooted in compost or water until roots grow.

The cuttings should be placed in a pot of compost or soil until they begin to root. Place your pot in a clear plastic bag to create a warm and moist environment that will allow the roots to grow. It’s not essential, but dipping the base of your cutting in rooting powder can aid germination and encourage new roots to develop.

Another way of propagating a cutting is to place the stem in a small container of water until the roots appear. Once the roots grow, it can then be potted on in a plant pot or bed in your greenhouse.

Before taking a cutting, it’s important to make sure your parent plant is healthy and disease free. Water the plant the night before and, if possible, take your cutting in the morning.

Division

The division method of propagation is when you separate one plant into several plants by splitting clumps of roots into sections, giving each section its own root system. Clump-forming plants include geraniums, rudbeckias, and many other hardy perennials. This is usually a useful technique for propagating types of plants that are prone to spreading or overgrowing, like grasses and ferns. It can also help give a second life to tired perennials that don’t look as nice as they used to.

To divide plants, simply lift the parent plant from the ground to reveal individual stems. Gently pull away each stem by hand or carefully divide with a sharp knife to separate them. Each new separated stem can now be treated as a new plant. Plant each new plant in a suitable pot filled with the correct soil type. Remember to replant the parent plant as soon as possible after division so it can recover quickly.

Propagating Bulbs

You can’t take cuttings from the stems and leaves of bulbs as the growing point is inside of the bulb, but there are many other simple ways you can reproduce your favourite flowering bulbs. Many popular bulbs multiply by naturally producing offsets, which are bulbs that grow from the basal plate of the parent bulb. You can remove offsets and either pot or plant them in a different area as the easiest way of propagating bulbs – this is the same as the dividing technique.

Some bulbs like tulips and lilies produce seeds when they die back and dry out. These can be sown like regular seeds; however, many varieties can take several years to grow to their fully flowering size.

A more advanced technique of propagating bulbs, especially daffodils or hyacinths, is by chipping. This method involves digging up and cleaning a leafless and dormant bulb and removing the paper outer skin before trimming back the roots and removing the tip. Then, cut the bulb into 8-16 sections, making sure each section includes a portion of the basal plate – these are your chips. Store these chips in a clear bag with a mix of vermiculite and water for 12 weeks. During this time, each chip will form bulblets between the scales. You can then pot these up individually and grow on in the right conditions dependent on the bulb species.

Many things will influence the success of your propagation, including the weather and the time of year you begin to propagate.

The timing of your propagation is essential. Most plants need propagated during their active growing period, which is different for each plant, but generally should be done from mid-spring to early summer.

You should also make sure the environment you’re propagating in has the optimal temperature and humidity levels. Use either a heated propagator or a propagator lid to achieve this. Other ways of aiding the quality of your plant’s environment include through misting or the use of grow lights.

Finally, choose the right soil for the plant you’re propagating. This will differ from plant to plant – for example, a compost specifically for seed sowing. Water your seedlings regularly and keep in mind that young plants will need watering more often. Don’t ever let the soil completely dry out but avoid drowning them too!

So, you’ve managed to propagate your seeds and cuttings successfully – congratulations! Your seedlings or stems should now have grown into young plants, sometimes known as plug plants.

Young plants are tender and can be damaged easily by improper care and low temperatures, so it’s important to look after them correctly. A cold frame is the perfect solution to protecting young plants, as it allows them to acclimatise to the outdoor weather while also protecting them from any cold spells. Once the roots start poking out from the bottom of the container, your young plants will be ready to plant out in their permanent position. Find out more caring for young plants in our guide on planting young plants.