Annuals are plants that go through a lifetime in one year from germination to maturation to reproduction and the end of life. Because of its brief life, the species survival depends on seed production in enormous quantity. In their natural habitat where weather conditions are ideal, most annuals produce thousands of seeds which nestle into the soil and germinate. Thus the species survives and increases year after year.
Annuals have a great deal to recommend them. They are easy to propagate from seed. The rate of germination is predictable and fast. Most have a long flowering season, in fact, nearly all the annuals grown at Government House bloom from early summer to frost.
Because they are single season plants and their root systems shallow, they require a bed of soil only six to eight inches deep. There are also more choices for ways to use annuals than any other class of garden flowers. At Government House, we’ve used them in the vegetable garden to add beauty to function. We’ve planted window boxes and planters with them, inventing new combinations to bring variety to somewhat predictable choices that dominate container culture. We also add annuals to our perennial beds to add colour to the changing patterns of the perennials. The primary use though, at Government House, is in a variety of beds throughout the grounds, beds they share with spring flowering bulbs. After bulbs fade in the spring, the beds are filled with annual transplants producing beds of colour lasting the full life of our growing season.
Annuals can be grown in almost any garden site. For most, full sun is best with half day sunlight being acceptable. There are also several genera of annuals that perform best in filtered light or shade. Any size annual bed can be sufficient as long as it’s not so large that you can’t reach plants easily to maintain them.
Set-out date: The most important first step is to establish a garden set-out date. This is simply the date when the garden is warm enough. It’s not only a question of air temperature but cold soil is as much of a problem as cold air. Ideally, I would calculate the set-out date by adding seven to ten days after the last expected spring frost as a margin of safety. Though opinions may vary, I consider June 15th as our last expected spring frost date. Therefore, planting anywhere from June 22nd to June 25th should ensure survival of most if not all transplants. Our set-out date at Government House has always fluctuated anywhere between June 15th to June 21st, but for good reason. There are not only weather conditions to consider but the busy Events that happen at Government House each week. On rare occasions in the past, we have replaced a few transplants by planting a little early. Plants set out prematurely will grow slower through cool weather while plants set out later will develop more quickly, thanks to milder temperatures and often mature about the same time as those planted two weeks earlier.
Seed Sowing: Though many seed publications still recommend direct sowing in the garden, I find that this delays the flowering season, so we sow all our annual seed indoors in advance of our set-out date. In our greenhouse, the conditions for growth are excellent and the seedlings grow large and healthy.
Ongoing Care: Overall, caring for annuals is relatively easy. Aside from pulling weeds, watering, fertilizing and deadheading are a constant throughout the growing season.
Fertilizing: At Government House, we have had great success using a 14-14-14 granular slow-release fertilizer mixed into soil before plants are set in. This fertilizer provides the necessary nutrients to plants over a 100 day period. Immediately after bedding plants are installed, we give them a drink of 10-52-10 plant starter fertilizer to aid in root development and help them become established. This is applied the first three weeks whenever deemed necessary and from that point on throughout the growing season we apply a 20-20-20 water soluble fertilizer every two weeks.
Deadheading: This simply means removal of dead flowers. If this isn’t performed regularly, the flowering season may be shortened considerably on some species. Deadheading prevents the plant from going to seed, allowing flowers to produce over a longer period of time. This task also keeps the garden neat and attractive.
Watering: When the sun is blistering hot and when plants have developed large root systems, the task of watering the whole garden becomes extremely important to the survival of most annual plants.
Because they grow and flower so actively all season long, annuals need a more constant supply of water than do other plants. The rule of thumb is that they receive an inch of water a week to penetrate six inches of dry soil.
We always try to water in the early morning of a sunny day. The reason being midday sun is too hot causing water loss to evaporation. And by waiting late in the day, the plants foliage remains wet into the evening inviting disease problems. We also water in fairly long periods so the soil is well soaked occasionally rather than lightly moistened frequently.
It would be remiss of me if I were not to thank the many volunteers that help make our annual planting each year a resounding success. What once took three men to complete in two weeks is now completed in two and a half to three hours, thanks to Her Honour Mrs. Crosbie and the office staff who work so diligently in organizing and bringing together dozens of volunteers who give so generously of their time.
With the extensive amount of annual beds located throughout Government House providing such a pleasant array of colour and the professional care provided to the beds and grounds by the garden staff, one should make it a point to visit such a unique setting. I would have to recommend August month to witness not only the annual beds at their best, but the rose, perennial and shrub beds as well.