Few things make me happier than the first round of blooms you get in mid to late spring from the annuals you planted earlier in the season. Seeing petunias cascading over the edge of a container or your marigolds growing bigger and getting ready to bloom is always a thrill but it is easy to take your eye off the ball and forget that to continue the beautiful display they need to be fed! Most perennial flowers require one feeding of fertilizer in the spring but for annuals to continue to look their best they need to be fed regularly. This leads one to a decision; do you use granular or liquid fertilizer?
How often I fertilize an annual plant and what fertilizer I use depends upon whether or not the plants are growing in a container or in a flower bed. I’ve grown annual flowers in containers for decades and tried both granular fertilizer that you get in a box as well as liquid fertilizer that you mix with water. Granular fertilizers carry a risk of burning and even killing your plants if they are not applied properly. They can be tougher to work within a container where plants expand and take over the pot. As a result, I use liquid fertilizers for containers as they are much easier to apply over the course of a long growing season and if they are mixed properly have a low likelihood of burning your plants. I feed the annuals in my containers every two weeks as the frequent watering that containers require can cause the nutrients to leach out of the soil pretty quickly.
Similarly, I have used both liquid and granular fertilizers in annual flower beds and deciding on which one to use is really a matter of preference rather than effectiveness. I’ve gotten great results applying liquid fertilizers every 2 weeks to my annual flower beds. The drawback for me is that due to the size of my garden this is a time-consuming task and candidly there are other things I’d like to be doing in my garden during the summer than fertilizing. As a result, I lean toward using a granular fertilizer in my annual flower beds as you generally only have to apply it once or twice a growing season. Granular fertilizer releases its nutrients over a longer period of time and this is a time saver for me.
An additional item that I wanted to be sure to mention is that while most annuals need to be fed there are some that don’t need it and frankly do better without it. Portulaca, for example, thrives in soils that are not enriched and if you give too much fertilizer to your Nasturtiums you’ll get a lot of foliage but not as many pretty flowers. If you’re not sure of how much fertilization a particular plant may need then consider becoming a Blooming Secrets subscriber and you can ask us directly! Finally, I often get asked about using organic vs. chemical fertilizers. Organic fertilizers generally don’t need to be applied as frequently and have a much lower risk of burning your plants. However, they are generally more expensive. Whichever fertilizer you decide to use I wish you lots of pretty flowers!
Photos Courtesy of Jill Mazur.