March's milder temperatures encourage gardeners to plan new beginnings.

It's time to begin weeding and cleaning up garden beds and checking out garden centres for ideas on filling any gaps left by fall cleanup and winter storms.

People with containers in shady places still have time to start begonia tubers. They are a multi-year investment, because they can be lifted and stored every fall and sprouted each spring for several years - and every year the tubers get bigger and produce more and more flowers.

Leaving seed heads in gardens over winter to feed birds can also be an investment in new plants when the seeds the birds miss sprout in spring or summer.

Among those easy seeders are alyssum, calendulas, lunaria, poppies, lupins, columbines, Nigella, and many others.

It's well worth watching out for them as you weed.

Usually it's best to keep some seedlings and remove others, because a thick mat of even the most valued varieties results in weak plants and small flowers.

During March, Hellebore orientalis flowers are in their full glory, but later, when temperatures rise, it's best to keep a watch on their pretty three-pointed seed heads, and cut them back before they dry out and dump masses of seed.

Hellebore seedlings are deep-rooted and hard to pull out.

When snowdrops cease flowering, they can be divided and started in new places. Anyone with a special variety of snowdrop who wants progeny with the same characteristics should remove its seed heads and rely on the natural splitting of the bulbs - because snowdrops are totally promiscuous.

Gardeners with enquiring minds will find that large groups of diverse snowdrops can produce fascinatingly different babies.

In the food garden, the timing of planting vegetable seeds outside depends very much on any garden's location, soil, and microclimate, because seed sprouting is triggered by temperature.

The sea tends to stabilize temperatures in coastal gardens, which means such gardeners can be planted several weeks earlier than those located further inland.

South slopes, sandy soil, and excellent drainage all help soil to warm up more quickly in spring.

Gardens close to the south side of the home are also warm and sheltered. But north-facing hillsides and moist clay soil are chillier, and need to be planted later, even when the gardener uses raised beds.

By the end of March, parsley, Swiss chard, peas, and potatoes can be sown in most places - and earlier in milder areas.

But if you're not sure when to plant, later plantings give less trouble, because if cold makes early planted seeds slow in germinating, they can't protect themselves. Voles love to eat pea seed, for instance.

Gardeners with sheltered places to raise tomatoes and peppers could start them around the beginning of March.

But it's easy to end up with huge plants that are difficult to keep inside but can't yet be put outside.

It's the same story with squash and zucchini. April is a reasonable time for starting inside. Some gardeners prefer mid-May for outside planting where squash and zucchini grow without check - provided you give them slug protection.

Throughout the garden, the best guarantee of a relaxing summer is to pull weeds while they're still small.

Mulching is also a huge help, although some gardeners avoid mulching places where treasured plants might have dropped seed.

Anne Marrison is happy to answer garden questions. Send them to amarrison@shaw.ca