Propagating Plants for Container Gardening

propagating plants

Propagating Plants

Propagating plants is a very cheap and easy way of providing extra colour in your gardening containers for really only minimal effort.

Annuals from Seed

Propagating plants is a very cheap and easy way of providing extra colour in your gardening containers for really only minimal effort. By raising a few annuals from seed, many new and ‘different’ effects can be won for our gardening containers. From a host of lovely things I can recommend to you Ageratum Blue Blazer and Summer Snow, Aquilegia (columbine) Dragonfly Hybrids and Antirrhinum (snapdragon) Floral Cluster. This last snapdragon blooms early and is particularly resistant to the weather, while A. Humming Bird is an excellent dwarf mixture.

Aster Lilliput Mixed is an attractive aster with double flowers which goes up to about 12 inches. A. Pinocchio Mixed is even more dwarf and my only grumble is that proper colour schemes are difficult with mixed seedlings.

Balsam extra dwarf Tom Thumb Mixed is very free with its flowers (8 inches), and I love Celosia plumosa (Prince of Wales Feathers) with its brilliant red or golden feathers; Dwarf Mixed, if you like a mixture and Fairy Fountains, another excellent colour range, is a little taller at 12 inches.

Annual chrysanthemums are always a favourite and I like Little Silver Princess which goes up to i8 inches for planters. Its flowers are white but for bigger containers do try Flame Shades and Suttons Special Mixture. Coxcomb (Celosia) Jewel Box Mixed (6 inches), Coleus Red Velvet and Eschscholzia (Californian Poppy) Miniature Primrose (5 inches) are other invaluable plants for inhabiting hanging baskets and boxes.

A friend of mine was extremely happy the year she started propagating plants and she grew Heliotrope or Cherry Pie in her window boxes for the perfume of the violet flowers, which she planted with dwarf single yellow dahlias, was a delight. Another year she tried an annual I had not seen before, Nemophila (Baby Blue Eyes) with white pansies and has plans next year for boxes of Phlox drummondii Twinkles which will fill the containers with a 7 inch high carpet.

I am very fond of poppies and already have plans to grow Papaver Alpine Mixed in matching hanging flower baskets and window planter boxes. Imagine 8-inch poppies peeping down over the edge of a low basket. Salpiglossis I have already tried and enjoyed them cascading their handsomely veined flowers out of the top of hanging flower baskets and other garden pots and planters.

Hardy Biennials

If you think of the word ‘biennial’ as bi-annual’ You will remember that this means two years, for a biennial plant sown as seed in spring or early summer comes into flower not that same year, like an annual, but the following year. It includes such favourites as wallflowers (cheiranthus in the catalogues sometimes), foxglove, dwarf Sweet Williams, etc. Seed can be sown early in heat indoors, but I prefer to sow in seed boxes outside in May—June, transplanting the plants into their flowering containers later in the year (September—October). They will stand fast and come through the winter safely out of doors.


A perennial is a happy plant which grows on for a number of years, certainly more than just one or two. Perennials, too, can be raised from seed if you have the patience, otherwise they are the easiest thing in the world to increase by dividing one root to make a number of new plants. I have found the easiest method of splitting is to plunge two garden forks back to back through the centre of the plant and then firmly lever them apart with their long handles.

Home Propagators

There are all kinds of small home propagators on the market for propagating plants – both for raising seeds and cuttings – some with special heating arrangements if you want to go in for this in a big way. I have found the small plastic rooting bags, specially designed for rooting cuttings, are ideal and attractive enough for the bags to sit on a window ledge or kitchen worktop, out of bright sunshine. You can raise up to 15 plants at a time this way. Everything is explained on the bag, and there are even dotted lines to show exactly where to cut the plastic for inserting the cuttings and watering. In the summer, when days are warm, geraniums will root within a few days, and within a few weeks make good little plants ready for putting into containers.

These rooting bags can be used a number of times, and certainly long enough to be able to satisfy the average person’s needs and provide a few extra plants to give away or exchange for other plants with friends. Another way which I have found successful for cuttings is to insert them all the way round a pot of good soil, putting the whole thing, after watering, inside a large polythene bag. Dipping the ends of the cuttings in water and then into one of the special hormone rooting powders assists speedy rooting.

The easiest cuttings to take from shrubs are perhaps those obtained by pulling off a side shoot with a strong downward movement which will come away with what is called a ‘heel’. Cut back any raggedness with a sharp knife, dip into hormone rooting powder, and plant in a pot. Any leaves low on the cutting should be removed.

Geranium Cuttings

When taking a cutting of a geranium (pelargonium), cut off a shoot of about 4 inches long from the growing plant with a sharp knife. Make the cut immediately below a node, which is the bit where the leaf joins the stem, for cuttings root easily from here. Cut away all the leaves except those at the growing tip. Place the cuttings into a mixture of equal amounts of silver sand and moist peat, or into a growing bag. Do not plant the cutting so deeply that its second node is covered. Geraniums are best left to root in warmth and, unlike most cuttings, do not like covering with a polythene bag.

Water only when the cuttings are really in need, and try to prevent water falling on the foliage, as this can lead to rotting. When roots have formed, the youngsters can be potted in John Innes No. 2 compost using 3-inch pots. At the same time, take out the growing tip, to ensure a bushy plant. Indeed, if you can brace yourself to nip back the sideshoots later on many more flower shoots will be produced, so giving just what we require —compact, stubby plants full of blooms, rather than skinny, leggy ones with only a few brave flowers on the ends of long stems. We can keep ‘stopping’ the plants in this way until around the end of May, when they can go into their permanent abodes and should be a fine sight within weeks, to delight us all summer long.

Cuttings, by the way, for flowering the following season are better if taken in August—September. If cuttings are taken with care from the parent plants it is possible they will not be missed, for the summer display will not be spoiled. Spring cuttings can be taken in March.

When propagating plants and space is scarce it is best to take cuttings in this way ready for next year’s baskets and boxes. They take up far less room than the big, bushy parent plants at the end of the season and so it is easier to bring them safely through the winter. An indoor window ledge in a cool room which is safe from frost, but yet gets plenty of light, is ideal.

Three 5-inch pots holding five cuttings each will give you 15 plants for next summer’s containers, and you can have more or fewer pots depending on your requirements. Stand them out of doors if you possibly can until the end of September. Give a liquid feed every week from January onwards. Plants should be ‘hardened off’ in early May. If you have a cold frame this means leaving the top off during the day, but if you are bringing the plants along indoors they can be put outside in a sheltered spot during the day and brought in at night. Put them into a cool room, of course, or the purpose is lost.

Do not be deceived by the mild, balmy days of May into putting the plants out into their permanent positions too early when you are propagating plants. Cold winds will make the leaves yellow, and our carefully-grown plants can be some months recovering from this harsh experience. Once planted and growing well, geraniums will flower best in sunny and even dryish conditions, though they must be fed and watered regularly. However, these ideal container plants will put up with more occasional neglect than most.

Propagating Fuchsias

You can take various kinds of cuttings from the fuchsia. The easiest way, in spring or summer, is to cut off a shoot immediately below a pair of leaves about 3 inches down one of the stems. Remove the two lower leaves and you have a cutting ready to go into a pot; a number of cuttings can be planted all the way round the edge of a pot, as with geraniums. Use a very sharp knife when taking cuttings, to get a nice clean cut for best results. Semi-hardwood cuttings are quite different, being taken from the plant when the ‘wood’ is ripe and hard at the end of the summer. Pull off pieces of sideshoot growing from the main stem. Each piece should be about 5 inches long.

Cuttings from Ivies

Remove portions about 3 inches long from the plant, again cutting below the spot where the leaf joins the stem. John Innes Potting Compost No. can be used, again placing the cuttings all the way round the edge of a pot, or else inserting them into rooting bags which can be placed on an indoor window ledge. Cuttings take about five weeks to root. Look at an established ivy plant and you will notice that it has long trailing juvenile growths and bushy adult growths towards the top of the plant. Propagate from the young trails. The bushier adult foliage is more difficult to root, and surprisingly only ever produces the less attractive adult foliage.

When you are propagating plants and the new plants have become really well rooted, grow them on in individual pots of John Innes No. 2 in a light place.  If you pinch back the growing shoots from time to time, good plants with close bushy growth will be achieved. Plant out into their permanent homes when established. To make a charming hanging basket with all-the-year-round appeal fill your basket with moss and John Innes No. 2. Five ivy plants all the way round and one in the centre make a really effective show. Those ivies with small or medium sized foliage are best for both baskets and boxes. Each spring, trim the long trails back.

Petunias and Bedding Plants

Fuchsias, geraniums, and ivies are probably the main stand-bys for container gardeners, but many plants normally grown purely as annuals and thrown away in late summer, such as petunias, dwarf lobelias, snapdragons, and wallflowers may be easily reproduced vegetatively for filling containers the following year. One or more plants, depending on requirements and the space available, should be lifted, potted, and brought into a greenhouse or frost-free sunroom.  In a south-facing glazed porch, I have had 100 per cent success for the winter. Take cuttings as with other subjects and pot them into rooting bags or pots of light sandy soil in spring.

For dramatic colour I suggest Salvia Red Hussar, Fireball (both about 12 inches) and Extra Dwarf Early Bird, another scarlet show stopper at about 9 inches. S. Compact Purple (12 inches again) with dwarf pink pelargoniums is another idea. Finally Zinnia Miniature Pompon Mixed at 9 inches and the coral Peter Pan Pink, rosy Peter Pan Plum and Peter Pan Scarlet make possible many original looking plantings so do try a few out for yourself.

Propagating plants can not only save you money, but can be very rewarding too.

05. September 2010 by Dave Pinkney
Categories: Annuals, Biennials, Container Gardening, Gardening Ideas, Plants & Trees | Tags: | Comments Off on Propagating Plants for Container Gardening


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