Water garden calendar, February

Here in the dismal UK the sun has begun to shine but it comes with cold air from the north and a thick layer of ice is back on all the pools. You would think the little world that seemed so active during the summer months was completely dormant. Not so, it is in February that a local district council near to where I live puts up its road signs warning of Toads Crossing. Suddenly, you realise that its the time of year those little amphibious monsters crawl out of their leaf heaps to get it on.

One of the gardeners best friends, they migrate in startling numbers to the place they developed as tadpoles to miniature toads. Females are always in short supply, so the adult males will attempt to mate with anything that moves including docile fish or another pair of mating toads. Sometimes there can be more than a dozen of males in a rolling ball in the pool - somewhere in the middle is a suffocating female. It is not surprising that the collective term for toads is A BUNDLE TOADS.

Toads on the march to their breeding grounds are one of the first signs of spring in the water garden.

Although the water in the pool has stayed pretty much below 10C or 50F you might think that might be another reason for nothing going on. In fact that is warm enough for the blanket weed or Spirogyra to take advantage of the lack of competition. An old client of mine with a wildlife pond was inundated with this green cotton woolly thread form of algae. He has no filtration or even moving water and his pool is surrounded by chalky limestone that produces very hard water in the pool, and blanket weed just loves that and it loves the phosphates that may drain in from the soil. This works as a dynamite tonic for the stuff. His only resort is to keep hooking it out with a lawn rake until the spring, when the rest of the pool plants kick into activity. The rest of the higher plant life will then give it a bit of competition and prevent the blanket weed from having sole benefit of the resources.

Even if you have of the resources of modern technology at your disposal, filters, chemical, U/V clarifiers and magnets on the water supply to the filter, once you have blanket weed it seems like you have got it for life. It does have its advantages if you can keep it under control, because it is always a ready vitamin rich snack for any of the vegetarians in the pool, especially the fish. And if youve got it, you will rarely get any other form of algae or if you do, then there is something seriously wrong in that environment.

Having said that there are some excellent products on the market that do remove the compounds in the water that help algae, and particularly blanket weed, to thrive. They do tend to be expensive but they are completely harmless to fish, animals and plants alike. The only trouble is they dont seem to work very well in conditions of high pH, which are the conditions these thread algae love.

Plants to look out for:

Marsh marigold , Caltha palustris, resolutely hanging on despite the frost and ice.)

The Marsh Marigold, Caltha palustris is resolutely pushing its way up. Whether it is a rock hard frozen bog area or sitting with its neck through an inch of ice in the margins, it is determined it is going to get out and about before the rest of the mayhem starts in the water garden. In fact its new growth for the following season starts in October when everything else is dying down, and despite the trials of winter, its little fleshy stems still manage to produce a golden display right at the beginning of spring at the end of March. The weather is usually still pretty dire then, so it is no wonder this has always been such a popular plant in this country, its bonny display encouraging wishful thinking about warm balmy summers.

Seasonal tips:

1.If you do have a filter in operation, make sure the pump is only turning over the surface water of the pool. Put the pump on the marginal shelf.

2. Keep it going until the temperature drops to 1 or 2C. Then turn the pumps off.

3. If the water freezes, dont be too worried for a couple days unless the pool is really dirty or overpopulated with fish. Rotting organic matter in the bottom of the pool will produce toxic gases that will poison the water if they are trapped under the ice. If this is the case, melt a hole in the ice with hot water poured into a saucepan sitting on the ice. The hole in the ice will allow gaseous exchange. Never smash a hole in the ice. Unfortunately this is a favourite pastime for kids, and in taking the first tool to hand it is invariable a fork or spade, the result is smashed ice, concussed fish and a punctured liner.

Melting a hole in the ice with hot water in a saucepan.

4. If you havent already done so, clear up dead leaves especially in the bottom of the pool before all amphibians start to spawn. Leave the detritus on the side of the pool for the sleepy beasties youve dredged up to make their way back home again.

5. Cut back, the marginal plants, trim the planting baskets from excessive growth. If all the growth seems on the outside and nothing in the basket, get ready to replant next month.

6. Look out for Herons; theyve got their eyes on your pool. Plastic herons wont deter them at this time of year. In fact they may do the opposite. Get out there yourself and mount an irregular patrol. Lack of routine is more of a deterrent to them than any scarecrow, especially if you do manage to catch them at it. They wont know when to expect you then.

Look out for the heron.