Are your container plantings starting to look tired and straggly? Have they already passed their prime? Are the numbers of blooms dwindling or are the plants starting to look leggy?
When the hottest days of summer hit, many container garden plants slow down on making flowers and fresh foliage — even if you keep up with watering.
Whether you have patio planters or window boxes, here are eight tips to maintain your container garden.
- If you find your pots are drying out too fast, you can use bark mulch on the surface to prevent the sun drying out the soil.
Heavy rains and high-pressure hose blasts dislodge potting mix and damage roots or pound the surface creating a hard crust through which water has difficulty penetrating.
Cedar bark has an added advantage: it has pleasant aroma that repels many insects, as does cocoa bean mulch.
2. There are some annuals that tend to become leggy or have stretched branching especially the trailing ones such as lobelia, trailing petunias, millionbells and potato vine.
If this is the case, it may be time to pinch back the length of the stem — by doing so, you will force out side branching.
When you pinch back the stems, you stimulate growth, making the plant bushier. With the new growth comes more flowers of better quality.
Pinch the flower stems back to just above a leaf or bud. Prune leggy stems back to buds or branches and removing off-coloured and damaged foliage.
3. Deadhead old flowers to promote new flower formation. By deadheading the spent bloom, you stop the plants from putting its energy into ripening the seed.
When you rob the plant of its seed you are also forcing the plant to producing more flower bus. Geraniums, dahlias, nicotina, verbena and zinnias, particularly, need deadheading.
4. Water frequently. Since containers don’t benefit from ground moisture, it’s important to water as often as once daily.
In hot, dry weather, you may need to water twice a day. This is especially true for closely-spaced plants packed into a small volume of soil.
When you water, be sure to saturate all the soil in the pot — not just around the edges.
If you find that your containers a drying out too quickly, perhaps you have too much plant for the soil in the pot.
If your plants are crowded, or just look past their prime, pull them out. As the summer progresses, remember that the plants grow larger and require more water.
5. Fertilize regularly with a slow-release fertilizer high in phosphorus (middle number).
Annuals are heavy bloomers so they are also heavy feeders. In containers, there is limited soil and frequent watering, so providing nutrients is essential for growing plants, otherwise they’ll weaken.
Add additional nutrients throughout the growing season. Frequency depends on whether you are using a liquid feed or granular.
Liquid fertilizer feeds quickly but gets leeched through the soil quicker and therefore needs to be used more often.
Granular fertilizers (including organic) slowly dissolve and provide a slow, but longer lasting feed.
6. Make sure you remove plant debris from containers. If left, decaying leaves and blooms often foster diseases and invite insects.
7. Rotate containers to encourage plants on all sides to grow evenly and don’t get too leggy.
8. As the seasons change, move your containers, if necessary, to keep the plants protected from very hot sun and sheltered from strong winds.
Joanne Young is a Niagara-on-the-Lake garden expert and coach. See her website at joanneyoung.ca
