Matthew's garden
beacons of spring
September moves summer gently into autumn. The destination into winter may not be where you want to go, but the journey is always a joy. It is a month of calm, tinged with loss, and that gentle sadness simply intensifies the preciousness of the present moment.
Bulb planting begins in earnest in September but continues busily into October with the one exception of tulips, which wait until November and even December for their planting.
Increasingly, I grow bulbs in containers, which means that we are accumulating more and more pots, and the one rule of a good pot is that it must be filled with something most of the time. So scillas, muscari, narcissi, hyacinths, irises and fritillaries are planted in gritty compost, along with pans of winter-flowering pansies and violas.
The larger pots see double or even triple service throughout the year, so bulbs are planted shallowly, often in big pans, and then removed after flowering and planted out to die back slowly so the pots can be replanted with a summer display. But as autumn progresses, it is the prospect of these displays of intense bulbs next February and March that sits quietly in these seemingly empty, grit-covered pots.
Early Colour
You don't need big, expensive containers to fill your midwinter garden with colour. Small pots, ranging from those roomy enough for a dozen small bulbs to a tiny one holding just a single snowdrop, look great both singly and in groups. I increasingly use terracotta alpine pans for bulbs and keep them in a cold frame, open at the sides but covered on top to protect them from waterlogging. I bring them into the greenhouse in relays to stir them into flower, from the end of January through to mid-March.
My favourite of the early bulbs are irises, particularly the reticulata, histrioides and danfordiae species. These early irises are all essentially alpine plants that only thrive in very sharp drainage and full sun - so they have little chance in Longmeadow's heavy soil, making them ideal for mollycoddling in a container. I plant them in an equal parts mix of potting compost and horticultural grit. Once the buds are an inch or so above the surface, I bring them into the greenhouse to open, then place them either on a table near the house, so they can be enjoyed from a window, or on a cool windowsill indoors. The key is to shelter them from too much rain and keep them cool, so they last as long as possible.
Iris danfordiae is bright yellow and one of the first to flower in mid-January. It is compact, so looks best in a shallow alpine pan. The bulbs are not expensive and tend to flower less well after the first year, so it is a good idea to buy fresh ones each year for the best display. I. reticulata flowers.
“As autumn progresses, it is the prospect of these displays of intense bulbs that sits quietly in these seemingly empty, grit-covered pots”
I also have the variety ‘Harmony', which has particularly deep-blue flowers with a gold blaze on the lower 'fall'. Its leaves remain quite stubby during flowering, but then grow taller to reach 30cm or more at maturity. 'J.S. Dijt' has rich reddish-purple flowers that open rather later, but is another superb choice.
I. histrioides is a member of the reticulata group. While the cultivar 'George' is especially magnificent, with rich plum-purple flowers that are rather larger than most others in this group, 'Lady Beatrix Stanley' has lovely blue flowers, with a yellow marking in the centre of the petals, carriedon a short stem.
All cultivars of I. histrioides flower strongly year after year for me and should ideally be planted as bulbs from mid-November. If planted in December, they would probably flower, but a lot later.
I also like to grow Narcissus 'Geranium' in pots. They have a lovely scent and once they start flowering, I move them to where we sit outside and enjoy their fragrance as well as display.
Planning for tulips
The thought of tulips lighting up next April and May is a beacon of hope that carries me through the grimmest of days. Although conventional horticultural wisdom has long decreed that it is best to plant tulips from Bonfire Night on 5 November up until Christmas, we did some trials on this when Gardeners' World was based at Berryfields near Stratford-upon-Avon. We planted a row of "Spring Green' tulips in the same bed, at the same depth, exactly a month apart, in October, November, December, January, February and March. The upshot was that we could find no advantage at all to planting in October and no disadvantage in going into December. January tulips flowered later and with slightly shorter stems. The February ones were radically smaller and later flowering, while March planted tulips did not flower and were clearly a waste of time and money. In short, try to plant in November, but do not worry if you have to wait until Christmas. Any left unplanted in the New Year should be placed in the ground as quickly as possible.
The reason for delaying until November is to avoid the risk of tulip fire. This is a fungal disease that initially often shows as twisted and mottled leaves emerging from the soil. You might see small pin-prick holes and lumps on the petals, and some visible grey mould on the leaves. The mould is a sign of the rot that can totally reduce a tulip to a molten-looking lump. By November the ground will be colder, so the disease is much less likely to spread.
​All tulips crave the same ideal conditions. They need really good drainage and as much sunshine as you can give them. Some buck this trend better than others, but if in doubt add masses of grit and keep them out of the shade. Extreme cold and heat will not bother them at all, but tulip bulbs hate sitting in wet soil for too long.
We plant our tulips in containers first, using the terracotta pots that are occupied by dahlias during the summer, so until these are cut back and put into storage the pots are inaccessible. We do sometimes plant tulip bulbs in plastic pots and then plunge these into the terracotta pots in spring, but they usually flower better if planted direct. This is because, when planted at a good depth, tulips tend to grow stronger and taller, within the limitations of the tulip type
On the other hand, if you are growing tulips in a border as part of mixed planting or as bedding, there is an argument for burying them just a few centimetres below the surface, where they can root into better soil. But this is only a good idea if the bulbs are to be lifted after flowering. If you want strong growth and any kind of permanent planting, then deep is good, and very deep is best.