Saturday, 14 September 2013


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We all love stuff that is free.  Plants can be very expensive to buy, and sometimes hard to locate.  If you have a little time on your hands and are armed with the right knowledge you can propagate many plants yourself from seeds, stem and root cuttings, grafting and division. 

Plants can easily be propagated from cuttings as they reproduce asexually from pieces of stem, leaves and roots to create a clone plant.  This is because the cambium layer, a tissue located just beneath the plant’s surface, forms a callus tissue once it is cut from which new roots and shoots can develop.

Taking cuttings or collecting seed is easy way to increase the plants you have within your garden for very little expense. You can take plant material from your plants to increase the numbers within your garden or to replace tired plants. Of course, you can also take material from different plants from your friends’ gardens or elsewhere to add variety to your garden. Just ensure that the parent plant you are going to propagate from is in perfect health as, with the exception of seed, the child plant will exhibit all the traits of its parent.

You can grow many plants successfully from seed collected from the spent flowers of many garden plants.  The main advantage of growing plants from seed is the low cost and high yield.  You can also source seeds of exotic or hard to find varieties that are just not readily available to buy as plants. Unlike asexual propagation techniques such as cuttings, grafting and division, plants grown from seed will differ from the parent plant. Growing plants from seed will lead to variation of plants that may differ in flower colour, vigour, habit and other characteristics.

Depending on variety and size of your seed you can sow your seeds direct into the soil of your bed, or in pots or seed trays. When sowing in containers use John Innes 'seed and potting' compost. Sow small seeds in seed trays and lightly cover with a layer of compost. Sow larger seeds in larger pots and place three seeds in each pot. As a general guide a 1.5 cm seed will require a 15 cm pot. You can use any container as long as it has adequate drainage (punch some holes in the bottom if it doesn't) . Don’t forget to label the pots!

Water lightly and place in a propagator, or cover with a sheet of glass/clear plastic bag/half plastic bottle. This will ensure that the seeds are kept moist until germination, after which this protection can be removed. Seedlings are at risk from fungal rots due to the damp conditions, so good ventilation is important. The seedlings will require high levels of light, around 12-16 hours of sunlight a day. A south facing window sill or shelf in glass house is ideal, although they will require the seed tray to be turned round daily to prevent the seedlings from permanently leaning. Keep the soil moist (but not waterlogged) until the seeds germinate, usually between 3 days to 3 weeks depending on plant variety.

You may wish to prick out some varieties of seedlings and transplant to larger pots. These pots can be filled with a standard potting compost or John Innes potting compost no.1 or 2. Wait until the seedlings have produced their second set of leaves and then lift the seedling out of the seed tray using a pencil/dibber. Hold onto the largest leaf and lift out the root ball carefully. Plant the seedling in the pot or in its final position and water gently.  The seedlings are ready to plant outside when the threat of frost is over, usually during May. Ensure you harden off the seedlings before planting outside by bringing them outside during the day and back in at night for a few weeks, or placing them in a cold frame.

You can sow seed direct into the soil from mid May onwards, when the soil has warmed up and the threat of frost has passed. You could sow your seeds a month or two earlier if you protect your seedlings by using a cloche. Prepare your soil prior to planting, incorporating a general fertiliser or organic compost as required for your variety of seed. It can often be an advantage to plant seeds in thin drills a few centimetres' deep. This allows for easier identification of the seedlings and differentiates them from other plants and weeds, which should be removed. Water well especially during dry spells and stake any tall plants as necessary.

Stem Cuttings 
Unlike plants grown from seed, stem cuttings will always be clones from the parent plant. This makes cutting especially effective where continuity amongst a group of plants is important, such as hedging or block planting. It is also useful to take cuttings of your more tender plants in case they do not make it through the winter.

Take stem cuttings in late spring/early summer when plants are growing vigorously. You need to select a stem from the new growth as this will root easier. Avoid flower buds as they will take the energy required to produce roots, although you can remove them if necessary. Cut a piece of stem 10 – 15 cm long, ideally just above a leaf node as roots usually form at a node. Remove the leaves from the lower third of the stem. If you are out place the cuttings in a container of water until you are ready to plant then up later that day. Take more cuttings than you need to allow for the fact that some will fail to grow.

Fill a 9 cm pot with John Inness seed and potting compost and water well. Make a hole your pot with a pencil or dibber and place the lower end of the cutting in the soil and gently firm. You can place three cuttings around the edge of each pot. Place in a partially shaded area either indoors or outdoors. Do not position in full sunlight as too much sun and heat will be detrimental.

When growing cuttings outdoors you may wish to place your cuttings in a cold frame or walled area to protect against drying winds. If you are propagating indoors place the pot in a propagator or cover with a plastic bag or similar to prevent moisture loss (I use half a coke bottle over mine). Water when the soil is just becoming dry, but ensure it is not waterlogged or the cutting will be prone to dampening off and rot. Your cutting should develop roots with a few weeks. A key indicator of success is that your cutting looks fresh and there is a little resistance when gently pulled.

Root cuttings
The advantage of taking root cuttings is that you can produce large numbers of plants relatively simply. There is no need for propagators or any fancy kit, you can just place them outside in a pot and wait for the plant to do its thing.

Root cuttings should be taken when plants are dormant, between November and February before the plant breaks out into bud. This is because the energy stored in the roots is absorbed by the plant during the growing season and makes roots cuttings less effective.
You can expose the roots of perennial and smaller plants by digging them up in their entirety. For larger plants such as woody shrubs you can dig down on one side to expose the roots in situ. Select healthy roots that are about pencil sized, avoiding old and woody ones. For perennial plants select the large fleshy roots, in fact the thicker the better. With sharp secateurs make a straight cut through the root closest to the parent plant. Follow the root down from this cut make a second diagonal cut towards the end of the root. The angle of the cut helps to orientate the root when you come to pot the root cutting up. This is important as your cuttings will not develop if they are planted upside down. Do not remove more than 30% of the roots of the parent plant or you will remove too much of the plants stored energy. Replant or cover the roots of the parent plant with soil afterwards and water well to settle the roots back into the soil.

Cut the root into sections 8-15 cm long, maintaining the straight top and slanted bottom angles of each cutting. Keep the width of each root about pencil sized as this will ensure that there is enough energy in each cutting to produce roots and shoots. You can plant your root cuttings direct into the soil or in deep pots. Water the soil well before planting so that it is moist. Dust the bottom of the root cuttings with powdered sulphur to help prevent the roots from rotting. Place some sand in the bottom of the planting hole and plant horizontally at a depth of 2-3 cm below the soil level. Cover with a 1 cm layer of coarse sand or grit and water sparingly, only when the soil becomes dry. New shoots should start to form in about a month. Feed with a weak solution of liquid fertiliser until plants are established when you can transfer to a larger pot or plant into the garden.

Grafting is the connection of genetic material from one plant to another so that they fuse together and grow to become a single plant.  You can graft a shoot of a plant onto the rootstock of another plant in order to create a plant that has the superior qualities of both parent plants.  The top part of a graft produces the branches, leaves, flowers and fruit and is known as the scion. The lower part produces the root system and the bottom of the trunk and is known as the rootstock. The scar where the two are joined is called the union.
Ornamental shrubs and trees are commonly grafted because it is difficult to propagate by other means. It is also favoured commercially as a larger flowering plant can be produced in a shorter period of time. Most plants need to be grafted within their own species but sometimes it is possible to graft within a genus.  A few plants can be successfully grafted onto different species, providing they are within the same family.

Grafting of ornamental shrubs is often carried out in early spring before the sap starts to rise, although it can also be done in autumn. Select your scion wood from healthy one to two year old wood and your rootstock from seedlings about two years old that are the thickness of a pencil.  Because you are cutting into the vascular system of each you plant you need to ensure that your knife is sharp and kept well sterilised in order to prevent spreading diseases. It is essential to make straight cuts to ensure that the rootstock and scion fit snugly.

With a sharp knife cut the scion wood just above a bud into 15-25 cm lengths.  Cut the rootstock down to 7.5 cm high and make a downward nick about 3 cm below the top.  Make a downward sloping cut from the top of the root stock to meet the first cut, and then remove the slither of wood.

Make a cut along one side of the scion wood the same length as on the rootstock.  Make a short angled cut at the base. Fit the base of the sion wood into the rootstock so that the cambium green layer beneath the bark meet, preferably on both sides of the stem. Wrap the union with grafting tape to hold the union until it fuses. You can place the graft in a  propagator or greenhouse.  Water sparingly but mist the plant regularly until it establishes.  The new graft should start to show growth in about six to eight weeks.

Division is as simple as it sounds. You make new plants by simply dividing the parent plant into smaller parts. The size of the parent plant determines how many plants you will get, but usually three or four new plants can be achieved. Division works on plants that have multiple stems (crown) as each new plant has enough stems and roots to create a larger plant. Plants propagated by division will always be clones of the parent plant and so will exhibit identical habits and characteristics. This can be useful when filling out borders, increasing your plant stock or replacing tired plants.

There are several ways that you can divide your plants but all are carried out at the same time; early spring or late autumn. This is because the plant is dormant during this period and the roots are inactive. Dig up the parent plant from the soil in one clump. With a spade cut downwards to separate into two pieces. You can further cut these pieces in half, depending on the size of your parent plant. Remove any dead, diseased or old plant material from the centre of the plant.

Depending on the type and size of plant you are dividing you may wish instead to use two forks back to back in the centre of the plant and lever the clump apart. This ensures that you do not sever any roots or the main crown which may happen when using the spade. You can then pull apart the clump with your hands. On tough rooted plants you may find that an old knife works well too. The key to successful division is to ensure that each section you divide has a good crown and root ball, as the new plant will establish from this genetic material. Ensure each division has at least two or three sprouts in its crown.

If you do not want to disturb or reduce the parent plant too much you can leave it in situ and remove a few divisions from the outside of the plant. Scrape back the soil from the edge of the plant to select the division you want. Take a spade and cut a square around the part to be divided in order to sever the plant roots. Lift the division and replant in its new position.

You can replant each division back into your garden or plant up in pots for growing on. Ensure that you plant them back at the same soil level in the bed as they were originally. Water well after planting and regularly during dry spells to ensure that the plants establish.

For related articles click onto:
Feeding plants
Growing herbs
Herbaceous borders
History of the lawn
How do I attract bees into my garden?
How to grow lavender
How to keep your cut Christmas tree
How do seedless fruits propagate
How to build a cold frame
How to grow artichokes from rooted cuttings
How to grow mistletoe from seed
How to make compost
How to propagate using division
How to propagate from seed
Plants for free
Preparing a seed bed
Watering plants

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