How do I keep full sun annuals blooming all summer?
Written by
Kiana Okafor
Reviewed by
Prof. Martin Thorne, Ph.D.Full sun annuals will bloom profusely with the right care and maintenance. Removing spent flowers weekly, called deadheading, will reroute any energy back into producing new flowers. Use a slow-release fertilizer at the time of planting, I prefer to use something like a 10-10-10 type of blend to encourage balanced growth. One of my clients zinnias produced 50% more blooms, after starting this kind of regular care with their annuals.
Pruning Strategies
- Shear petunias back by 1/3 in July to prevent legginess
- Pinch zinnia tips at 12" (30 cm) height for bushier growth
- Remove lower marigold leaves to improve airflow
Feeding Schedule
- Apply liquid seaweed every 3 weeks for root health
- Side-dress with compost tea during heatwaves
- Stop fertilizing 6 weeks before first frost
Optimizing sunshine is an absolute must. Aim for 6 or more direct hours of sunlight a day. You may need to trim back some overhanging branches if they obstruct anything in the garden. A client's shaded garden gained an additional 2 weeks of bloom time after she had a tree limb removed that was shading her garden area. Rotate the plants so that they all get some amount of direct exposure.
Common Issues
- Yellow leaves: Overwatering, check soil 2" (5 cm) deep
- Sparse flowers: Increase phosphorus fertilizer
- Leggy stems: Move to brighter location
Pest Solutions
- Spray aphids with soapy water at dawn
- Dust diatomaceous earth around beetle-prone plants
- Handpick hornworms wearing gloves
Monitor your advancing efforts. The journal of another gardener who monitored temperatures informed me that lantana bloom cycles were optimal at 95°F / 35°C. Use your bloom cycle counts as a way to document in social media. You could even tag some of the peer horticulture groups to share your counts and compare your gardening approaches. If care is consistent, gardens can turn into extravagant displays throughout the summer. Now, go make those flowers work for you.
Read the full article: Full Sun Annuals: Blooms That Thrive in Sunshine
