Increasing your plants by seed and cuttings At this time of year, it pays to deadhead many herbaceous plants and some shrubs. This means cutting off the flower stalks once flowering has finished and ideally before the plant sets seed. Not only does the plant look nicer not having (soggy) dead petals hanging limply on it while the remaining flowers poke through but removing dead and dying flowers also stimulates the plant to continue sending up new flowering stalks and buds. This means you get a longer period of flowering (which also feeds more insects). However, not all plants react the same. Some, such as weigela and paeonias, are single flowering, meaning they will only produce a set number of flowering stalks and so your deadheading efforts will make the plants look tidier but will not stimulate more flowering. If you keep a look-out as to how the plants in your garden behave, you will start to build up a picture of how to treat them. Roses are a complicated group and if you are unsure of how to proceed, try to work out what form they take. Shrub roses tend to be large and, well…shrubby. They tend to be tall, from 1 – 4 meters high, single-flowered (only flowering once), and if the spent flower heads are left on, they may go on to produce colourful rosehips (berries). Smaller rose plants are either hybrid tea roses or floribunda roses. Very tiny ones are patio roses. The latter two have numerous flowers per stem, whereas hybrid teas tend to be stiffer, more upright, and often have just one large flower per stem. They are repeat flowering if deadheaded regularly, as are the patio (miniature) roses. The floribundas are also repeat flowering but produce many smaller blooms on shrubby plants. Climbing roses fall into two categories: climbers and ramblers. Climbers tend to have stronger shoots with large flowers. They are often repeat flowerers, so deadhead them. Ramblers are floppier and more bendy, often quite vigorous and earlier in flowering. And just to muddy the waters, there are roses which seem to fall between the two categories. Now is also a good time of year to increase your stock. One way is to save seeds. Seed collection is great fun, and with a few simple guidelines in mind you can often collect lots of seeds successfully from the plants you like best. This might mean sacrificing some flowering time and letting the plant ‘go to seed’. In our climate, I prefer to let the plant develop seeds midway through its flowering season, not waiting till the end in case the weather turns wet. We all want good germination from any seeds we collect or buy, and the vigour of the seeds and seedlings is highly dependent on the health of the mother plant. A well-nourished and disease-free parent will pass on far more nutrients which will be stored in the seeds themselves, so aim to collect from the best parents. As a start, save your paper envelopes from letters and junk mail. Do not store your seeds in polythene (even the degradable version) as this will not allow the seeds to breathe and they may rot. The only time polythene is useful is when stratifying to germinate seeds (see below). If you watch the developing seed-heads carefully, you will see them going darker, drier, and/or more woody looking. Keep observing and you will see the ripest of them start to split down the side or open out in other ways so the seeds fall out. Try to be on hand just before the seeds disperse, which can be a fine art of timing! You can collect the seeds either by shaking the plant and catching the seeds as they fall, or by cutting the seed heads off and popping them into the paper envelope or onto a tray, stalks and all. The seed heads should be as dry as possible. Alternatively tie a paper bag over the seedhead before the seeds disperse. Once collected most seeds can be spread out if damp and air dried at room temperature or left in the envelope open to the air. After they are well dried, remove as much dust and debris as possible, as this may harbour fungi, and put them in their final packet, label and store in a cool, dry place out of direct light. Don’t use polythene unless you are sure they are very dry. Plants have all sorts of mechanisms for dispersing their seeds. They provision the seeds well, but then mother plants really do want their seed children to leave home and for the new plants to grow well away so that there is no competition. The seeds are booted out by numerous means. Methods include:o flying (maple seeds have wings)o exploding (violas, broom)o sticking to passers-by (goosegrass/sticky willie)o floating (coconuts)o passing through guts (berries, i.e., rowans)o wind (plants with catkins such as willows, or fluff, like dandelions)o collected and buried (jays and squirrels bury acorns) I collected some viola seeds once and had them drying on the windowsill. A friend sitting 3 meters away was hit in the eye when the seedpods exploded. On a sunny day in summer, you can hear broom pods cracking as they jettison seeds. There are some seeds which don’t store well or need different treatment. Primulas and oaks need sowing soon after they ripen. Cones will need laying out in a warm place to help them open and shed their seeds. Many conifers grow in areas prone to forest fires and the cones shed their seeds once the fire moves past. The seeds have bare ground in which to germinate, with no competition. Many berries (and some other seeds) can be kept dry during storage but need stratifying to germinate. Stratifying can be complex, but if you have a few seeds the easiest method is to sow them into a pot, label, protect them from pests, and put them outside for the winter period. You can also put them into a polythene bag with moist vermiculite, seal, and put into the fridge. Label, as always. More on “stratifying” in a later article. For the moment, though, all you need to do is to collect into labelled envelopes and then dry them (or sow them, if appropriate). The next stages will be weeks away. The time involved is in observation and pouncing as soon as the seeds are ready. The sheer variety of seeds and their differing requirements is staggering but very absorbing to explore. It is a great way of getting to know plants. It gives you such an insight into some of the complex ways plants negotiate the world, coping with weather, predators, people, and competition from other plants. These next few months are also a good time to take semi-ripe cuttings from many hardy deciduous shrubs such as weigela and philadelphus (pictured). Semi-ripe cuttings are taken from the end of a non-flowering branch that has just started to ripen, which means the base of the 20 – 30cm cutting is firm but the top is still growing. These are nodal cuttings, i.e., the base cut is just below a node (leaf joint). Remove the lower leaves at least halfway up the stem and insert the cutting into a pot full of a half -compost and-half-vermiculite mix. Water, cover with a propagator lid or a clean polythene bag, and place in light shade. Turn the bag inside out once a week and remove any diseased leaves. When you see growth, make ever larger slits in the polythene to let air in gradually over a period of a few weeks, before removing the bag altogether. Leave them in the pot until roots are visible at the base before potting individually.Happy gardening!