Attention, celery fanciers: Now's the time to dig up celery and plant it indoors to ensure a winter supply of the crunchy, green stuff.
Celery does quite nicely indoors; it's less sensitive to the stresses of transplanting -- less sunshine, less air circulation and higher temperatures -- than some other flowers and tender perennials. If it's at all practical, keep the celery in a cool part of the house. Below-freezing temperatures won't hurt it -- only prolonged or extreme cold (below-20 temperatures) will.
Plant the celery in a large and roomy pot. Fill it with the same ordinary garden soil the celery is growing in now. Because the plant is likely to be large and bushy -- mine is a good two feet tall and perhaps 12 inches in fullness -- you need the extra soil for weight to keep the pot from toppling over. Also, if the plant is that large, it will have a very well-developed root system that has to be accommodated.
Celery is a tolerant plant and won't suffer too much with a little rough treatment. When you dig the roots, allow a good radius of earth around them so you don't cut into them. But shake off quite a bit of the excess earth to make potting the celery a little easier. When potted, the crown of the plant and the soil level should be at least two inches below the rim of the pot. The soil shouldn't cover the crown. Water well, after packing in the soil, and put the celery plant in a bright, cool area. If you have to make a choice, go for light or sun, but remember that your new houseplant will do better in the coolest spot.
Pick stalks individually as you need them, starting with the large outside ones and working your way in. You'll find new growth will spring up where light and space allow it. You may get a whole new celery bunch developing where you've cut just one stalk for flavoring the vegetable soup.
I find that it's a waste of time and energy to blanch; unblanched celery has considerably more flavor and modern celery varieties don't require the tenderizing effect of blanching. However, some traditionalists wouldn't think of eating anything but pale green or white celery. If you do want to blanch your celery, wrap a layer of newspaper around the stalks and tie with kitchen string, but not too tightly. It should take at least two weeks to blanch. Leave the tops unwrapped and keep your plant well watered, for celery is a thirsty character.
If you decide against potting celery, think about getting some in now for chopping and freezing. It will do fine in the garden for a while longer, but you may just forget about it and find frozen mush in the garden later this year. Better to take advantage of it now.