When I was growing up, celery was served almost invariably as a summer salad vegetable – and it is very good like this. But cooked celery enriches almost any soup or stew, as well as being tasty in its own right.
Celery and its close relative celeriac are both delicious now. Celeriac is cultivated for the swollen, knobbly base of the stem and should be thought of in the same way as a carrot or parsnip (although it needs much richer soil than either of them).
It did not reach this country until the late 1720s and has never really entered the popular culinary imagination. It is an earthy, rooty thing but delicate and delicious when cooked and very nutritious, unlike celery, which, when tough, probably needs more energy to digest than it supplies.
Neither crop is entirely straightforward to grow, but they’re hardly difficult. I sow the seeds of both in March and put them on a heated mat to germinate.
Monty Don (pictured) has been exploring the delights of growing celery and its close relative celeriac – the perfect ingredients to any warming winter soup
Q I planted tulips, mini daffodils, irises and violas in pots. Can I remove the violas and store the pot with the bulbs until next year?
Allan Brown, Dundee
A Yes, although next year’s bulbs will perform better if repotted into fresh compost. After flowering, put the pot in a sunny place, and water until the foliage of the bulbs has died back. Then put in a corner and keep dry until early autumn.
Violas planted in a terracotta pot (stock image)
Q Are my potted mimosa and lime hardy enough to leave outside or should I move them to my greenhouse?
Lorraine Harding, Hastings
A I would not risk the lime (I’m assuming you have a citrus rather than a tilia, or lime tree) and the mimosa will only take a touch of frost. Best to overwinter them in your greenhouse.
Mimosa (stock image) will only take a touch of frost
Q Is it possible to leave dahlias in the garden through the winter?
Alan Taylor, Lancashire
A The deeper the tubers are planted and the better the drainage, the safer it is to leave them outside with just a mulch for protection. But the combination of wet and cold is the greatest problem, and if your soil is heavy or you live in an area where frosts can drop below -5°C I’d dig them up and store them in a cool, frost-free place.
The combination of wet and cold is a risk for dahlias (stock image)
The initial seedlings are tiny and when large enough to handle I prick them out into plugs and keep them growing under cover until May.
It is important then to harden them off properly for a couple of weeks before planting out.
Celery occurs in Asia and Europe in marshy, boggy ground and the secret of both crops is a constant supply of water.
I used to put young celery plants in a trench in a double row with about 23cm between each plant.
Then, when the shoots rose above the top of the trench, I filled the soil from the ridges back round them so that only a little green leafy topknot showed.
This created a kind of earthen clamp around the maturing hearts which protected and blanched them.
But now I only grow self-blanching kinds, which are planted onto the surface in a block, shading each other and so blanching the stems.
Blanching is necessary to make the stems sweeter and more tender by blocking out light (it also works with endive, cardoon stems and forced rhubarb).
You only need to do this for about two weeks before harvesting, and it can be done by wrapping newspaper or cardboard around the stems – but I find planting in a block works perfectly well.
Celeriac is, in many ways, easier to grow than celery, although it does take longer to establish a harvestable crop.
The swollen base does not develop until the leaves are well established, and needs good-quality soil and plenty of water.
Soil with lots of organic matter will make a huge difference both in retaining water and in helping it to develop a really good root system that will grow deep to find all available moisture, and this can dramatically reduce the watering you need to do. I sow the seeds in March.
They are tiny, like those of celery, so I scatter them thinly on a seed tray – do not cover them – and then prick them out into plugs.
These then get potted on into 7.5cm pots.
Although celeriac is quite hardy, it is a mistake to put it outside too early because it will not grow in cold soil – and while it sits, waiting, like the rest of us, for spring warmth, the slugs tuck into it with relish.
So I wait until mid-May before planting mine out 30cm or so apart in blocks or rows.
If the weather turns really cold, both celery and celeriac can be protected by mulching with a thick layer of straw or bracken, although one Christmas I had to dig celeriac out of the frozen ground with a pickaxe.
It was not ideal – but at least we were able to make celeriac purée to go with our festive turkey. It is an excellent combination.
Monty’s plant of the week: Mahonia x Media ‘Charity’
There are a number of good mahonias, all with varying virtues, but the first to flower in my garden is M. x media ‘Charity’.
It has soft, primrose-yellow flower spikes that usually open around now, and then continue through to early spring.
Its evergreen leaves are very broad and prickly and, left to its own devices, it will grow to 2.5m or more.
Monty’s plant of the week is the Mahonia x Media ‘Charity’ (pictured) which has soft, primrose-yellow flower spikes
After flowering it can be pruned hard, with the long stems taken right back, and the bare stems will break into lateral growth.
It is happy in shade and is therefore ideal for a north-facing corner or under a large tree.
This week’s job: Protect good terracotta pots
Some terracotta pots are more weather-proof than others.
Beware that terracotta is porous, so absorbs water – either bring them in under cover to be kept dry or wrap them in hessian or bubble wrap to provide some insulation.
Monty has warned that the the best way to protect vulnerable terracotta pots is to wrap them in hessian to provide insulation (stock image)