It’s time to start your detective work! There are many reasons for troubled plants.
The basics of plant care are:
Water
Food (fertilizer)
Sunlight
Temperature (climate)
Protection from parasites and diseases
This is a pretty simplistic view of things but you’ll need to check each one of the items above to identify the problem.
Water: All plants need water. If they get too little, they will wither away. Leaves will yellow and then turn brown and drop off. When they get too much, they can get root rot or other fungus infections. They can wilt and die. Sometimes the plants will turn black and “melt.”
Food: Each plant variety has its own specific needs. We published an article on fertilizer on June 24th. Please refer to that for more information. Too much or too little of each component can create problems. Imagine if you tried living on only candy or only celery. You wouldn’t be very healthy!
Sunlight: Putting a shade plant in full sun or a sun-loving plant in full shade will have consequences. Don’t do it unless you want your plants to die.
Temperature: When you purchase plants or seeds, the seller will usually provide information on which USDA zone is proper for that plant. If you’re unsure about the zones, read more at https://en.m.wikipedia.org/wiki/Hardiness_zone Plants live in specific climates with minimum and maximum temperatures, amount of rain, humidity, etc.
Protection from parasites and diseases: Some plants just thrive no matter what you do and some are more delicate. Some are sensitive to fungi, insects and diseases. Some are favorites of deer, rabbits and other animals. Whether you install fencing or use natural or chemical means, your plants often need some help to get through the season.
Do your research or contact your local garden center or county extension service. They want you to succeed.