Monty’s tips for spring
It is all a bit of a gamble but over the years I have learned that by observing the following few pieces of advice you have a fighting chance of growing a pretty wide range of tender plants even if you have a cold, wet garden like mine.
From early April, we retrieve any tender plants in winter storage. Dahlias are checked – any rotted or shrivelled tubers discarded – and the good ones potted tightly with a little compost and put into cold frames, or on benches in the cool greenhouse to kick them into growth so that by the start of May, when the risk of frost is diminishing by the day, they can be planted out as healthily growing, robust plants. Cannas are watered regularly for the same reason and citrus plants placed outside but with fleece handy to cover them if there is a late frost.
We’ll tentatively unwrap tree ferns and cut back the old fronds. Depending on the temperatures through early April, new fronds (or croziers) should be apparent by now, albeit as green hoops waiting to uncoil.
Tender plants, whether a here-today, gone-tomorrow annual or 100-year-old tree fern, do best when there is a reasonably constant temperature without too much change from day and night – and at Longmeadow at least, that can mean waiting until June before they start growing properly. Patience is the key – everything will catch up in the end.
◼ Be wary of a sudden improvement in spring weather. It is always better to be too late than too early.
◼ Harden off properly anything that has been stored under cover over the winter months. In practice this means putting it outside in a very sheltered spot for at least a week, and preferably two, then planting it out and having some fleece to hand as extra protection if there is a late cold snap. ◼ Wind chill applies even on quite mild days. Therefore shelter from wind can make all the difference and you can create a more benign microclimate with judicious use of walls, fences, hedges and neighbouring shrubs.
◼ Do not overfeed plants as this will just promote lush growth that is too tender. Let plants in the soil take the nutrients that are available. Those in containers should be fed no more than weekly.
◼ Lush tropical plants, such as cannas and bananas, need an awful lot of water. So if they are in pots you may have to water daily in hot weather.
◼ Drainage makes all the difference. A really good soil structure, with plenty of organic matter that will retain moisture without becoming waterlogged, will always be warmer and healthier for tender plants than a cold, wet one.
◼ You can’t control the weather. Every now and then you are going to be caught out, so don’t worry if you lose some plants. It happens to everyone, in time. floriferous cousin, the common garden dahlia, are equatorial plants from central America. They provide an intensity of colour which is invaluable when creating a jungle feel, and I like to mix jewelcoloured dahlias, such as ‘Grenadier’, ‘David Howard’, ‘Chimborazo’ and ‘Ambition’, with cannas.
Stars of summer
The combination of vivid, flamboyant flowers and enormous, striking foliage makes cannas some of the most dramatic plants in any garden. I particularly like the mixture of dark or striped foliage with the brilliant orange flowers of ‘Wyoming’, plus ‘Black Knight’ which has red flowers and ‘Durban’, with its colourful striped leaves and bright orange flowers. Canna ‘Australia’ is enormous – certainly too big for the pot that I first planted it in – but, with its burgundy-black foliage and bright red flowers, it’s perfect at the back or centre of a large border to up the ante in pure extravagant lushness. Canna roots are fleshy and able to store enough food to take the plant through its dormant winter season. However, they are not frost hardy so they will require protection.
The richer your soil the more cannas will like it and they should always be generously mulched after planting and never allowed to dry out if they are to flower well. Each individual flower lasts only a few days, but more will be produced from the same flower spike until there are no more buds. It should then be cut back to the next sideshoot, where a secondary spike will appear. Most cannas will produce three or four spikes by the end of the season.
Bananas raise the foliage stakes even higher and Musa basjoo is one of the hardiest, down to -5°C. In 2014 I was very taken by a display at Hampton Court Palace Flower Show of a dozen or more of the
Abyssinian banana, Ensete ventricosum, with its enormous purple leaves set with rich plum veins. As a result I ordered two for Longmeadow and they became the stars of the garden for the remainder of the year.
Ensete needs sun and very rich soil, so add lots of compost or manure when planting and then keep it well watered and fed, as it is a plant with an appetite to match its huge size.
Banana plants are not at all hardy so they do need proper protection before the first frost appears – but they will be perfectly happy otherwise between mid-May and October. And, as warm weather returns, reinvigorate them with fresh compost and they will power away – all latent energy and
ABOVE Dahlias may be overwintered
under mulch in milder, drier gardens LEFT Explore different varieties of canna as leaf colour will vary enormously
vigour, ready again to steal the limelight.
I should note here that, although in the past I have routinely lifted and stored tender exotics, things are changing. As discussed in several of my recent Full Monty columns, last year I decided to rethink my approach, particularly with those tender exotics previously used in the Jewel Garden. Some are now planted permanently on the Mound, and although they may receive some protection in situ through winter, they will have to largely fend for themselves. I will also be drastically reducing the number of plants that we store over winter across the rest of Longmeadow. As a result, the garden, particularly the Jewel Garden, will look very different. I am excited by this and regard it as more of an opportunity than a loss.
Monty Don will appear at BBC Gardeners’ World Live at the NEC Birmingham (13-16 June) on Thursday 13, Friday 14 and Saturday 15. For information and tickets visit bbcgardenersworldlive.com
Bananas are not at all hardy so they do need proper protection before the first frost appears