Browning edges, spots or discoloration or a combination start appearing on leaves of many plants in the last month of summer. Do your best to provide consistent watering and the plants should survive.
You might see brown edges on leaves of a plant that rarely has problems.
Leaves draw water from the roots and expire moisture through the day as part of photosynthesis.
During the drought in July and extreme heat, plants showing this damage couldn't get water to the leaf tips fast enough to replenish the moisture lost to the heat.
While the edges are drying out, moisture from overnight dew can also 'magnify' the day's heat and burn some leaf tissue, creating a spotty effect.
Overhead watering can also create these spots on leaf surfaces.
These spots and brown edges are dead leaf tissue.
Add the Powdery Mildew fungus that develops during hot and humid weather to the weakened leaf tissue and you get dissolving leaves.
Other fungus that blows in or splashes up during heavy rains will also latch to the weakened leaves.
Drought followed by heavy watering or rain also causes plants to 'give up' some leaves.
Early leaves that formed during the ideal temperatures and moisture of spring are not the right structure to help the plant in this 'new environment.'
The leaves aren't helping in photosynthesis; so, plants shed the non-functional leaves to grow new ones or go into early dormancy.
Remove dead leaves and dispose of them in trash (not compost) to avoid spreading any fungus.
Keep things evenly watered by adding a watering routine during dry spells. Water at the base of plants early in the day to keep water off leaves and minimize evaporation.If you still have healthy, unaffected leaves, you could try applying fungicides to healthy leaves now to prevent the spread.
How to avoid fungus next year:
- Fertilize in the spring at the beginning of the growing season to keep plants resilient against the myriad of pests out there.
- Plan to apply fungicides to protect theplants that were affected this year.
- Start applying per directions in late June.
- Follow the above watering directions.
All photos above provided by customers who contacted Ward's with questions.