"brianb" wrote in message
...
I am doing some landscaping on my own and have very little knowledge
unfortunately.

A perennial: Does that mean it grows back year after year without
having to be re-seeded? That's what I would think.

Basically, that is true. What is perennial depends on the climate.
I.e., what is perennial in Florida won't necessarily be perennial in
Minnesota. In addition, some plants are perennial, but short lived.
Two examples which spring to mind are columbine (Aquilegia varieties)
and candytuft (Iberis sempervirens). These last three or four years,
then lose vigor and die out. Some plants are biennials; these grow
leaves only the first year, flower the second year, then die. An
example is the moneypenny (Lunaria, I think).


Do these perennials spread automatically? That's what I would want
for groundcover and whatnot.

Perennials come in many sizes and growth habits. Some spread, either
by seed or by runners, and some don't spread much. An example that I
can cite from personal experience is Amsonia tabernaemontana, which
forms a clump but doesn't otherwise spread. However, the seeds sprout
generously, creating thousands of new plants every year.

Groundcovers are generally treated separately. For example, Vinca
minor, myrtle or periwinkle, is a perennial, but because it stays
relatively low, is evergreen and spreads like crazy, is categorized as
a groundcover. I.e., groundcovers are perennials but perennials aren't
necessarily groundcovers.

You need to assess the characteristics of each plant you intend to
grow for height, spread, hardiness in your climate, adaptability to
sun or shade, type of soil and moisture requirements and growth habit.
The wide variability among plants in these characteristics means you
should be able to find plants for any conditions.

Having said that, be aware that the characteristics in books don't
necessarily match what happens in your garden. Even though you are in
zone 6, let's say, like I'm supposed to be, some plants hardy to zone
6 in the books will die in hard winters and others will do just fine.
Gardening is a continual learning experience - you essentially write
your own gardening book for your yard bit by bit as you go.

Good luck,

Guy Bradley
Chesterfield MO
zone 6