A common question I get comes from people looking for perennials that bloom all season. Someday I will get brave and tell someone "if you want continuous bloom plant annuals."

To me the whole purpose of a perennial garden is to reflect the seasonal change that comes from grouping plants that bloom at different times and for different periods of time. The challenge with perennials is to find a combination of plants that are happy in your garden and provide a colorful show all season long.

Of course there are perennials like coreopsis, re-blooming daylilies, scabosia, and gaillardia that are a basis for a long season of bloom. Several days ago I saw a statement that would suggest another.

It said that if you don't know what to plant at a spot plant a perennial geranium. Don't confuse perennial geraniums with the annual everybody calls geraniums. This is a huge group of perennials, long favored in England, which should be more widely planted in our gardens.

My experience is that the shorter (height) the geranium variety you select, the more extended the blooming season, and the more sun it will tolerate. Usually the geranium is thought to be an edge of the woods plant, but I have been quite successful with the short ones in full sun.

With geraniums expect a strong late spring bloom and regular but more sporadic bloom thereafter for the rest of the season.

The non-blooming spring shrub question came up again. This time it was a lilac. After fielding the question I went to check on the six or eight lilacs I have planted over the last four years. All were blooming well.

This takes me back to one of my common refrains. I planted them, watered a bit at planting, probably forgot the fertilizer and never pruned them. Before you think I am negligent, I did scatter a little mulch and have done a fairly good job of eliminating the weed competition.

The question asker had pruned last fall which is a sure fire way to eliminate flowers on spring blooming shrubs. For my taste, there was also a bit too much love with water and fertilizer. A wildly growing plant has little desire to bloom. Excess fertilizer and water causes excessive growth, which usually reduces bloom.

Lilacs like a fairly neutral soil so a bit of lime and no acid fertilizer may help, but they are quite adaptable so I doubt that this is an issue.

The final question for today is "Is it safe to plant?" Last week's effort to answer that question was shaky. The weatherman lied. He said nothing below 40 degrees in the next ten days and we immediately had two stiff and one light frost. I saw a low of 31 degrees. I had followed my advice and escaped with only a minor nip here and there.

For you traditionalists, Mother's Day is past so it's safe to plant, but to be honest, I'm still a bit jittery about the real tender ones until I see warmer temperatures.