Why are my eCHINACEA FLOWER PATCHES getting smaller each year?

[slackmax]

I have clumps of Echinacea flowers growing along my split rail fence. Each year the clumps get smaller. A six foot long clump is now 5 feet long, etc.

Rabbits like to hide in them, ANd I have moles in my yard. Are moles or rabbits eating them?

I fertilize them moderately each year.   

I never see any destroyed echinacea plants, just smaller clumps each year.


Thanks in advance !

[Sibley]

Are you deadheading? Specifically, are you deadheading later in the season? Because if so, you're preventing them from seeding.

[Dicey]

Ha! Our Azaleas are failing to thrive. We blame the moles that seem to be eating their roots.

[monarda]

Are your echinaceas the native varieties or something fancier from a garden center?
Ours are native and spread and spread. The ones I've bought from garden centers or farmer's markets never last.
(I can mail you seed heads of my native guys if you'd like, just throw them on the ground)

[rosarugosa]

I used to have a large stand of purple echinacea, but groundhogs wiped it out completely.  In recent years, I've been able to grow some e. Santa Fe successfully. The bunnies do seem to find them irresistible, and I see signs of heavy nibbling despite my liberal use of Plantskydd (although the Plantskydd has generally been quite effective).

[slackmax]

Answers to questions: 

No, I am not deadheading at all. I wait til the Spring, then just break off all the stems a few inches above ground. I get lots of birds feeding on the flower seeds, and hopefully dropping the seeds along the fenceline.  By doing nothing myself, the echis have spread nicely along the fenceline, from bird droppings I assume. But existing clumps are shrinking every year.

Groundhogs. Hmmm. I did see a groundhog outside my fence a few weeks ago.

Native vs storebought. Don't know. I think we bought them as small plants 30 years ago.   I have tried planting seeds, and sometimes they actually come up, but usually nothing happens. Have tried planting  seed pods from the actual plants, and they sometimes come up. 

I think they must be propagating in some spots, too.   

Hot lately. I have been watering them every day. Usually I never have to water them, but some of the flowers are falling off, I assume due to all the heat and no rain.

[the_hobbitish]

Could you be over watering? I think they only need about an inch a week and are usually better off with one or two good soaks instead of daily watering to encourage deep root growth.