Tag Archives: step by step garden guides

Outdoor Classroom: twin scaling

photo 1 - Copy1) Twin scaling is a way of increasing the number of bulbs more quickly than by other usual methods. A single bulb can yield up to 30 or more baby bulbs (bulblets) over a period of a season. It only works with proper bulbs – not corms, tubers and rhizomes. Bulbs need a base plate and a layered construction to be twin scaled – eerily similar in form to the common onion shown here.
photo 2 - Copy2) Twin scaling works well for bulbs such as narcissi (daffodils), crinums, galanthus (snowdrops), nerines, amaryllis, hippeastrums, lachenalias and some lilies. Wash the bulb and remove any outside coating and old roots. Make up a weak solution of household bleach – about 1:10 bleach to water – and dip the sharp knife and bulbs. Clean working conditions and hygiene are important to prevent disease and the transfer of any viruses.
???????????????????????????????3) Remove any offsets already formed, making sure you keep some of the base plate with them. The base plate is where the roots grow from. Cut the top third off the bulb (both offset and top are visible to the left in the photo). Cut the main bulb into quarters or eighths, depending on the size of the bulb. Each piece must have some of the base plate remaining attached. The larger the bulb, the more sections you will get.
???????????????????????????????4) Peel off two scales together, attached to some of the base plate. Keep your knife clean and sharp so you can cut through the base of each section more easily. It does not matter if you have three or more scales but if you do not have part of the base plate, the process will not work. A bulblet will form between the two scales on this base plate.
photo 5 - Copy5) Plant the scales in a pot or tray filled with seed raising mix. Press them down deeper than in the photograph until just the tip is visible. Water them in and keep the tray in a warm, reasonably dark position. The bulblets will form through the autumn and grow away in spring so it is best to twin scale when the bulb is freshly dormant. It is too late to twin scale autumn flowering bulbs because they are already starting to grow but you can do the spring flowering ones which includes narcissi such as this bulb.
???????????????????????????????6) If you lack the confidence to take each section down to two scales, you can stop at step 3 where you have cut the bulb into quarters or eighths. As long as you look after them, most sections will grow away into healthy, independent bulbs. It is probably easiest to start with a large bulb while you gain confidence. Most bulbs propagated by twin scaling will take at least two years to reach flowering size, sometimes longer.

Outdoor Classroom: multiplying succulents

Photo 1If everybody realised just how easy it is to strike succulents from cutting, nobody would buy these plants unless they were new or exciting. This Crassula ovata (Jade Plant or money plant – very good for feng shui, apparently) could easily generate 30 good sized plants or many more smaller ones.
Photo 2The ground-hugging types which form rosettes are easy to lift and divide. As long as they are replanted in full sun with excellent drainage and light soils, each little rosette will form new roots when nestled into the soil. Tidy up the rosette first by removing dead leaves to avoid them holding moisture in the rotting foliage.
Photo 3Even succulents with well defined branches will grow. This is Aloe plicatilis or the fan aloe. Unlike usual leafy cuttings, succulents can be struck from very large pieces and you can expect close to 100% success rate. Cut to a balanced shape. Place the cutting in an airy spot and leave it for a few days to dry out. This reduces the chance of rotting before it creates roots.
Photo 4Stick the cutting into a pot filled with a free draining potting mix (we use granulated bark) It is better to use a mix which does not have much fertiliser in it but this is not critical. You can equally put them straight into the garden in a free draining, dry position. It may be necessary to stake the top if you have a heavy cutting so that it remains standing. Do not try and keep it firm by compacting the soil or potting mix because you want maximum drainage.
Photo 5Make sure that the cutting does not get waterlogged while you wait for it to form roots, but it will need an occasional wetting. In a few months, most plants will have started producing roots but it will take time for a large or heavy cutting to develop enough of a root ball to keep it standing upright.
Photo 6Most succulents, including the popular burgundy black aeonium whose name few can remember and even fewer can spell (Aeonium arboreum ‘Zwartkop’ or ‘Schwartzkopf’), sempervivens, aloes and many cacti can be increased this way. It is a good activity to share with children.

Gardening 101: Dividing perennials

0011) Clumping perennials can get overcrowded and start to deteriorate over time. Some will stop holding their flowers up well, some can die out from the middle while others just look tired and messy. Some need digging and dividing relatively frequently to stay looking their best. This clump of pulmonaria (unromantically known as lungwort) probably started as a single crown two years ago but grows rapidly.
0022) Dig out the clump, shaking off the soil. If you are not sure what you are doing, hosing off the dirt can make it easier to see the structure of the root system which varies between different plants.
0033) Part the leaves to find the separate sections growing from the centre or crown of the plant. Some plants just pull apart. An old carving knife is helpful and a meat cleaver is good for larger clumps with tough crowns. You can use a spade but it is hard to get accurate cuts. The pulmonaria yielded at least 15 divisions, all of which would grow as separate plants if I wanted that many.
0044) Replant the strongest divisions into soil which is well dug and friable. If you are only lifting and dividing every 10 years or longer, this can be a major task as soils compact over time. If you are doing it more often, it is easy as the soil stays looser. Spread the roots evenly and cover to the same level it was earlier. We like to add compost mulch and then water thoroughly but gently. Removing some leaves reduces the stress on the plant.
0055) These three perennials also benefit from lifting and dividing every few years. From left to right: an aster which just pulls apart into separate sections, mondo grass (ophiopogon) which also pulls apart but sometimes needs the runners snipped, and polyanthus which usually needs to be cut through the crown to ensure that each piece has roots attached.
0066) This patch of stachys (lambs’ ears) was dug and divided three weeks ago and has already recovered well because it is in full growth. Timing is not critical in our mild climate but done in midsummer, care needs to be taken to avoid the roots drying out and plants will need thorough watering for the first week.

First published in the Waikato Times and reprinted here with their permission.

“A good soil, like good food, must not be either too fat, or heavy, or cold, or wet, or dry, or greasy, or hard, or gritty, or raw; it ought to be like bread, like gingerbread, like a cake, like leavened dough; it should crumble, but not break into lumps; under the spade it ought to crack, but not to squelch; it must not make slabs, or blocks, or honeycombs, or dumplings; but, when you turn it over with a full spade, it ought to breathe with pleasure and fall into a fine and puffy tilth. That is a tasty and edible soil, cultured and noble, deep and moist, permeable, breathing and soft – in short, a good soil is like good people, and as is well known there is nothing better in this vale of tears.”

Karel Capek, The Gardener’s Year (1929)

Lifting & limbing – the before and after of careful pruning

1) This garden aspect is generally all right but you would not look twice at it. The large tree is a weeping cherry, Prunus subhirtella pendula. The fact that the left hand tree, a malus or flowering crabapple, has no leaves on it in high summer is a bit of a giveaway. It is dead.

2) The malus is showing fresh growth at its base but as we knew it was a grafted plant, this is just the root stock growing away.

3) Spend some time working out which branches need to be removed. You can’t glue branches back on and it is surprisingly easy to make a mistake. We are taking off the lower branches and a few higher ones which extend too far over the adjacent gardens. We used a squirt of paint to mark the branches destined for the chop.

4) Make an initial cut underneath the branch. This prevents the branch from ripping off and damaging the bark when you cut from above.

5) Cut close to the trunk or main stems. Don’t leave ugly stumps which resemble protruding coat hooks. There are different schools of thought about whether wounds need to be painted with an antibacterial paint. In this case we have coated the wounds but we don’t usually bother.

6) The dead malus has been removed entirely, even the main stump. If you can get most of the root ball out, it reduces the chance of honey fungus or armillaria getting established on the rotting roots and potentially spreading to surrounding trees. The cherry tree now has a more pleasing shape and it is possible to see beyond the tree and to notice other garden features in the same view. Successful pruning is often discreet – quite a bit of material is removed without it being obvious where it has come from.