Perennials (defined as plants that last through many years by becoming dormant in the winter and re-emerging each spring) are often on sale as the summer progresses and when good garden centres begin to think about fall. Therefore, it’s a great time to pick up some new perennials to refresh an existing flower bed or to begin a new flower bed. While shopping for perennials, be sure each plant is healthy. Plants should have rich colour in foliage, overall vigour and bud/bloom/evidence of bloom past. Below are some of the most common questions about perennials that we field in the summer months:
Q: Is it OK to plant or move perennials in the summer?
A: Yes! It is recommended that perennials not be planted (or split/moved) in the heat of the day. Soil amendments should be added to the new planting space – compost, triple mix – and all new transplants must be well watered upon planting and then for two to three weeks after. Transplant fertilizer can be used to facilitate the process of adjusting to the new location. Staking may be required while the stalk of the plant strengthens.
Q: What are Tender Perennials?
A: Tender Perennials are plants that are not exactly for our “zone”. In Peterborough city we are Hardiness Zone 5; north of Lakefield is best described as Hardiness Zone 4. On perennial plant tags Hardiness Zones are listed. Plants in zones 2, 3, 4 and 5 are appropriate for these areas. Plants at zone 6 and above will only over winter in warmer climates. Even some zone 5 perennials struggle to re-emerge in the spring when we have a hard winter (cold and not a lot of insulating snow) and we call them “tender perennials”. Perennial Hibiscus and Butterfly Bush are good examples of “tender perennials”. We can be more successful with them if we cover them well with mulch or shredded leaves in November and try to cover the heart of each plant with snow whenever possible. Tender Perennials should be planted in sheltered areas. It is recommended to enjoy these tender perennials, just don’t plant a hedge of them and invest large sums of money and/or make an emotional connection to them as they may not make it through a harsh zone 4/5 winter.
Q: Why deadhead Perennials?
A: Removing the spent blooms of perennials keeps them tidy looking and fresh. Plus, it gives strength to the plant and often a second or third flush of bloom emerges as a “thank you” for your efforts. Some perennial varieties look old and ratty mid-summer no matter what we do to them, so they are best to be cut down and a lovely seasonal pot placed in front to fill the space.
Q: Should I fertilize perennials?
A: The best fertilizer you can provide to your perennials is good soil. A rich, well draining soil or nutrient rich compost should be added regularly, not only upon transplanting. Consider adding fresh soil or compost each spring. It will add volume to your soil that has compacted over the winter and add important nutrients to the plants. If you wish, water soluble fertilizer or granular slow release fertilizer can be added once a year (usually spring). If you fertilize too often, the roots of your perennials will stay shallow, looking for the food you give so freely and will not grow deep in the soil (where it is warmer in the winter) looking for food and moisture.
Yes! Perennials are on sale at Griffin’s Greenhouses throughout August. Call for details or log on to our website: www.griffinsgreenhouses.com