Friday, February 14, 2014

Perennials or Annuals?

 Perennials above, annuals below.

I always smile to myself when customers come to the greenhouse and ask me to help them choose plants for a perennial flower garden because they are tired of buying plants every year, and they want “low maintenance”.  Those of you who have perennial flower beds know why I smile to myself.

There are advantages and disadvantages to having perennials, also with annuals.  To clarify the issue, Perennials are plants that come back every year.  Some die right to the ground, others keep their leaves, but they grow back in spring.  Annuals are plants that die when winter comes.  Hardy perennials are those that will survive winter in Zones 1-3 or 4; Half-Hardy perennials may survive if you take the time to protect them, or if you have an out-of-zone microclimate.  Tender perennials will only survive in high-number zones.

Need yearly replacing, but are relatively inexpensive
May be expensive in the
initial purchase
You might start your own from seed
Most can be divided to
multiply the plants
Seeds vary from inexpensive to very expensive
You can share/trade plants
with neighbors/friends
Plants that are grown from cuttings usually cost more than those grown from seed
Starting from seed is a very challenging process.  Seeds can be expensive; collecting seeds is not reliable as they might not be true to type
Preparation and Maintenance of
Flower bed
The bed can be totally
Cleaned in the fall, and
perennial weeds can be easily dug or treated with weed killer
Ideally you would start with a weed-free bed.
At the end of the season, cut back and clean plants.
In spring, clean up if necessary, look for signs of perennial weeds.
Weed control after planting
Regular cultivating and weeding during the summer
Regular cultivating and weeding during the summer
Some perennials scatter seeds which will grow in spots of their choice.  Most will have to be weeded out.
Use mulch that can be dug in when fall comes, such as compost or well-rotted manure (smells like dirt, not poop).
Semi-permanent mulch such as wood chips can be useful in retaining moisture. 

Mulch does not control annual weeds that grow from seeds blown in by the wind.
Slows down, but does not control perennial weeds.
Keep mulch about 4-6” away from the base of the plants.
Bloom all season long, many well into fall
No perennial blooms all season.  To have season-long color in a perennial bed, it is necessary to find a variety of plants that each bloom in their own time, yet the collection provides color all season long. 
There are many plants that have lovely foliage even when they are not blooming.

Why are perennials hard to grow from seed?  Some perennials are not difficult, usually the ones that produce masses of seed.  Think of perennials in nature.  The parent plants are likely to survive the winter, so fewer seeds may be produced.  The seeds of one plant are variable in their germination time:  some sprout next year, some may lay for years before sprouting—consequently the rate of germination for us growers is poor.  Most perennials need the freeze/thaw cycles of our winter and spring, to germinate.
(That’s why your delphiniums and columbines will germinate better if you seed them outside in the fall.)  Many seed-grown perennials take several years before they bloom.

Why are annuals easier to grow from seed? It’s like the plants are programmed for reproduction, since the parent plant is sure to die.  They produce many seeds which usually germinate more easily. (Note:  many seeds need to be left uncovered for light to trigger the germination process.  Some need a warm environment; others need a cool environment.).  Consult a good gardening book, or a good seed catalogue for advice on the individual needs for seed germination.
My Personal Preference:  Mixed beds of shrubs, perennials and some annuals tucked here and there for color the whole season long.

1 comment:

  1. I think by 'low maintenance' most mean 'no maintenance' and such does not exist. Neither can the effect shown in your annuals photo be accomplished with two trays of little plants. Sigh.