If by “geraniums” you mean the popular garden and container plants often sold as Geranium (Pelargonium), May is an important month for setting them up for a long season of blooms.
10 things to do in May for continuous flowering until frost
- Move plants into full sun
- Geraniums flower best with at least 6 hours of direct sunlight daily.
- More light generally means more blooms and sturdier growth.
- Wait until frost danger has passed
- These plants dislike cold temperatures.
- Only place them outdoors permanently when nighttime temperatures are consistently above about 10°C (50°F).
- Refresh the soil
- Use well-draining potting mix in containers.
- In garden beds, add compost to improve fertility and drainage.
- Feed regularly
- Start a routine with a balanced liquid fertilizer every 2–4 weeks.
- Too much nitrogen can produce lots of leaves but fewer flowers.
- Pinch growing tips
- Pinching the tips of young shoots encourages branching.
- More branches usually means more flower clusters later.
- Deadhead spent blooms
- Remove faded flowers as soon as they decline.
- This prevents seed production and directs energy into new blooms.
- Prune leggy stems
- Cut back weak or stretched growth.
- The plant responds with fresh shoots and a fuller shape.
- Water deeply but not constantly
- Allow the top layer of soil to dry slightly between waterings.
- Overwatering is one of the most common causes of poor performance.
- Watch for pests
- Check for aphids, whiteflies, spider mites, and caterpillars.
- Early treatment is much easier than dealing with a large infestation.
- Provide adequate spacing
- Good airflow reduces disease problems.
- Crowded plants are more prone to fungal issues and weaker flowering.
For the biggest flower display
The combination that usually makes the biggest difference is:
- Full sun
- Regular deadheading
- Consistent feeding
- Avoiding overwatering
When these four factors are managed well, geraniums can produce vibrant flowers continuously from late spring until the first autumn frost.
