Perenial spring, summer and fall blooming plants for sunny garden
by Gretchen
(McVeytown, Pa 17051)
How many plants should be put in a 9X15 garden with a front and side views? This garden will be viewed by passengers on the trains and rail fans.
Doug says figure the "average" perennial takes up 1.5 square feet of space at 3 years of age. So you have 135 square feet of garden. So without knowing what you want to grow - this is the rule of thumb.
So "roughly" 90 plants will fill all that space within 3 years.
Having said that - if you want it to fill faster - then you either have to plant more or use plants that grow quicker or start with larger plants (bigger pot sizes). And then plan on digging/dividing and removing them as they grow and meet each other in year three.
If you don't mind waiting a bit - you can get by with fewer plants.
Or buy larger 2-gallon sized perennials instead of 4-inch pots.
Hope that helps.