Chrysanthemums

CHRYSANTHEMUMS      

Although the summer is now well and truly behind us, September is the peak season for garden chrysanthemums. Most gardeners can find room for a few of these plants in the garden or allotment, and if you have some spare glasshouse space after the tomato crop you can extend the season into November or even December in a mild winter or with some added heat if frost threatens.

The starting point for most folk is the admiration for those magnificent blooms on display at a flower show, or growing on some ones allotment, especially if they are showmen and are just about to take the paper bag off a flower that is ready. Everybody wants to know what is under those bags. Then, can the grower be persuaded to part with a cutting knowing that you just might end up being a competitor. However those first few cutting are very special and get maximum attention lavished on them as you try to grow them to the highest standard. There is always a but, and as you do not have the years of experience of the serious competitor, your results are brilliant but not yet quite ready for the show bench. However they will make excellent cut flowers for the home.

Once the bug gets under your skin and you grow for exhibition, this hobby is very demanding of your time, but the end results can be very satisfying.

Other chrysanthemum enthusiasts may be quite happy to grow for garden and allotment display and cut flower for the house.

Types of chrysanthemums and season

If you are an exhibitor you will need to be aware of the official classification to enter your blooms in the right category for showing, but if you just want to grow them for garden display and cut flower you do not need to get bogged down trying to sort out the differences between a reflex, incurve, spray, anemone, fantasy, single or whatever else you find in the chrysanthemum catalogue.

However, whether you buy from the specialist grower such as Woolmans or Harold Walker, or get a few cuttings from a friend, keep the type and name recorded as you will need to know its season and whether it gets disbudded or not.

There are several excellent chrysanthemum growers who can supply collections of one type or another so every year you can try out something new, keeping those you really like, but discarding the rest if they don’t meet your needs.

The first blooms usually come from the early outdoor  chrysanthemums in late August and September. These can be incurved, reflex, or sprays.

These are followed by the October flowering varieties of incurves, reflex or singles usually as sprays which will all need some weather protection in a cold greenhouse.

The November and December varieties will also need protection and also some heat if cold weather prevails. The October to December flowering plants can be grown outdoors in pots or baskets planted in soil all summer then brought into the greenhouse in mid autumn.

Chrysanthemums are also grown as pot mums as a house plant flowering all year round. Flowering is controlled by adjusting the light level duration with polythene blackout curtains, and growth is kept dwarf with a chemical growth retardant. The amateur gardener does not have access to the growth retardant, so although many people retain the pot plant to grow the next year, it will revert back to its normal height and may not be suitable as a pot plant. However some height restriction can be achieved by frequently pinching out shoot tips to make it branch, though this has its limits.

Propagation

At the end of the season plants are cut down to six inches and the stools dug out of the ground shaking off the soil then boxed up in fresh potting compost. These can be overwintered in a cold frame or cold glasshouse as long as it is fairly frost free. They are hardy, but don’t push it.

I had a lot of plants in 2010, so left many in the ground to overwinter. None of them survived and even in the cold glasshouse many died out as the winter was long and cold. Keep the stools on the dry side, but add some water if necessary to keep them alive. Start them into growth in January or February. Take cuttings about two inches long from the stool and dip them in rooting hormone and dibble them into pots boxes or cellular trays in a free draining rooting compost. Place this in a warm light place but not in direct sunshine. They should root and be ready for potting after three weeks or so. Pot up in small pots, then larger pots in a soil based compost. Plant out in late spring.

Growing

They can be grown in well manured soil spaced at fifteen inches apart and staked individually with a cane. If you grow a big batch it is quicker to grow them in a two foot wide bed and secure them with a roll of six inch weldmesh or wire fencing. This is held tight between four posts and raised as the plants grow. I plant mine at one plant in each square and do not pinch out the tips to allow one flowering shoot per plant.

If you grow sprays you do not need to disbud, but if you want one large single bloom you need to disbud leaving just the one terminal flower bud to develop. Remove side shoots as well as flower buds.

Keep them fed, watered and weeded throughout the growing season

Pests and diseases (some)

Chrysanthemums can be prone to attack from a wide range of pests and diseases, but the main ones are greenfly, slugs, leafminer and earwigs and the two main diseases are white rust and mildew.

In modern times with very few chemicals left on garden centre shelves, the answer is vigilance and good growing conditions.

On a small scale it is possible to spot and remove most pests before they do any significant damage, and fungicides containing myclobutanil, available for rose problems will help control diseases, but any leaves affected by white rust should immediately be removed.

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The Growing Season

SPRING PROPAGATION

Early April is a time when gardening really gets serious. Seed sowing of vegetables and flowers is in full production, chrysanthemum cuttings are being rooted, begonias started and plants germinated earlier are now needing pricked out or potted up. My greenhouse is always full even though I keep putting out plants to harden off as other younger more tender plants take their place. Outdoors I will be preparing the ground for the first sowings of vegetables and flowers, then if I can find a few spare days there is fences to be repaired, outdoor tables to paint, the greenhouse glass needs a wash,  my allotment shed roof leeks badly, and now the weeds have started to appear.

Fat chance of me taking advantage of some nice warm day to make sure my sun lounger is still in good working order. However my winter art classes are now finished till after Easter when I start again with a ten week summer session, (information on my website), so I will have no excuse for not getting some gardening done, unless of course I find my latest art project too stimulating to leave. I am currently working on new paintings for the Aberdeen Arts Fair in August where I will have a stand. My beautiful bright red Amaryllis was perfect as a colour prop in one of my figure paintings.

Greenhouse activities

Sowings of broad beans, onions, lettuce, early summer cabbage and cauliflower are now big enough to get hardened off so they are now outdoors in a sunny sheltered spot. They all went into cellular trays so did not need pricking off. This gives me a bit more space for my tomatoes now that they have been potted up and are growing strongly. They should be ready for planting into the growbags next week, but that depends on the weather just in case we get a late cold spell.

Overwintered geraniums are looking great. The largest ones are now outdoors, but younger smaller ones need a bit more warmth to bulk up.

Grape vines propagated last year from cuttings are now all breaking into growth, so they are due to get hardened off very soon. My greenhouse grapes are also starting into growth, so I ventilate on all warm days to keep a buoyant atmosphere so I don’t get troubled with mildew or botrytis.

Seed sowing continues with sweet corn going into small cellular trays to be transplanted into larger ones after germination.

Cape gooseberry seeds are also going into cellular trays as well as kale and Brussels sprouts.

Tuberous begonias have now come out of storage in the garage. I overwintered them in polystyrene boxes filled with a mixture of dry soil and sand, but now the warmer atmosphere has plumped up the buds which want to get growing. I start these in boxes packed quite close together covered lightly in compost, but they will get potted or boxed up again when they start to put on more growth. I have had about thirty non stop tuberous begonias for over fifteen years. The tubers get big enough in time to split in half as long as there is a few buds on each portion.

Chrysanthemums have had a hard time overwintering in my cold greenhouse, and I may lose some varieties, though it is early yet. Time will tell. I have started to take cuttings as they are big enough, (about two inches long) inserting them into trays. They will enjoy a bit of warmth on the living room windowsill to get them rooted, and then it is back into the greenhouse. I have a collection of early outdoor reflex and incurves which get disbudded to give me large heads and another collection of sprays which do not get disbudded. They are grown in a bed system on my allotment, giving a glorious display before getting cut for the house.

Outdoor work

Leeks can now be sown thinly in a well prepared seed bed outdoors. Once they are pencil thickness and about six inches tall, they can be lifted, topped and tailed, dibbled into big holes, then watered in to firm them up. The variety Musselburgh is always a good favourite. They are heavy feeders so make sure the ground for them has been well manured or composted, and still give them a dusting of fertilizer.

Dogwoods and willow growing in the winter border have now been pruned right back to ground level. This always seems very harsh, but they are very resilient and soon grow back quite strongly. I encourage growth with a dressing of compost in winter, then some fertilizer in spring. It is the fresh one year old shoots that give the brightest colours.

Landscaping works

Several shrub roses have been removed as they just were not strong enough to fight off attacks of mildew, rust and blackspot. They were growing on a very steep bank, so now I have to seek plants that can stabilize the soil and prevent erosion of soil running down the slope. Last summer I planted drifts of flag iris that have surface rhizomes that soon cover the ground holding the soil in place. They were supplemented with polyanthus, which were spare after they finished their spring display in tubs. They are brilliant at hugging the ground and continue to flower all spring. I will be adding a batch of Shasta daisies that are also great for soil stabilization, and once the threat of frost has passed I have a dozen young Fuchsia Mrs Popple ready to go out.

To add variety and cover other areas of this steep slope I am growing a batch of Cosmos which will go under glass for a few weeks to get them started, and a sowing of the annual Shirley poppy will go straight onto the steep sloping ground. I will prepare a fine tilth and add a sprinkling of old growbag compost to assist the germination, but they will get no fertilizer, otherwise it will be plenty of growth at the expense of flowers.

Early spring bulbs

The spring bulbs continue to flower. Now it is the turn for the Scilla siberica, Anemone blanda, grape hyacinths, early narcissi, and tulip species. February Gold is one of the first narcissi to flower, and the kaufmanniana tulip Stressa, Shakespeare and Show Winner are in bloom at the end of March. These are followed by the Fosteriana types such as Red Emperor and the white Purissima and the greigii hybrids Red Riding Hood.

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