The Real Benefits of Gardening With Perennials (And How to Grow Them Well in Tennessee)
Perennials also provide financial security‚ as perennial plants will return year after year‚ unlike annuals which must be purchased each year anew․ For Tennessee gardeners in USDA Hardiness zones 6b through 7b‚ perennials are a better investment than annuals because the humid growing conditions of summer and sudden frosts late in the season disrupt the growth of annual plants․ A well-planned perennial bed will provide some flowering in spring‚ summer and fall‚ so that you don't have three weeks of color followed by weeks of nothing․
Perennials are practical for Southern gardens․
Most perennials will grow a root system their first year‚ and really show their stuff in year two or three․ The difference between working with perennials versus annuals is that with annuals, you want them to look great all season․ With perennials‚ you're building something up that springs back thicker and bigger every year: the hosta or coneflower you plant this April will be twice as big next summer․
They also combine well with other woody elements in the garden‚ and perennial and ornamental grass plantings‚ low conifers‚ or flowering shrubs can be layered in for year-round interest even when nothing is flowering․ This is especially important in Tennessee‚ where the growing season is long enough that a garden with only spring flowers looks tired by August․
In Middle Tennessee and East Tennessee‚ deer pressure‚ clay soils‚ and high humidity in the summer months are the three biggest challenges for gardeners․ Most perennials, as a class, are more tolerant of all three factors than picky annual bedding plants would be․ Most varieties tolerate our red clay as long as it is amended‚ and many plants‚ including coneflower and black-eyed Susan‚ are drought-tolerant once established․
Book: Caring for Perennials: What Actually Matters
Perennials do require less fussing than most people assume‚ but there are a few things․
Soil preparation for planting․ Tennessee red clay holds moisture and compacts easily‚ suffocating roots․ Working two to three inches of compost into the soil before planting your perennials will help them root in and require less maintenance later․ You probably want to work this whole area of the garden if you're planting an entire bed‚ rather than just one plant․
Watering‚ especially the first year․ Keep newly planted perennials well watered in their first 6 to 8 weeks in the ground․ Aim for about an inch of water each week if there is no rain․ After the first season‚ except for dry-condition native plants‚ nearly all perennials require supplemental water only during dry periods‚ and in some cases ornamental grasses or plants like yarrow may do better with minimal watering once established․ These will quickly develop root rot compared with being drought-stressed․
Fertilizing for soil quality․ In cases of low fertility as indicated by your soil test (popular in old Tennessee lawns that have never been amended)‚ an early spring application of a slow-release‚ balanced fertilizer can help․ However‚ if the soil already contains plenty of compost‚ you do not need to add fertilizer because excessive nitrogen promotes leaf growth‚ not flowers․
Deadheading and cutting back․ Pruning and deadheading are used to redirect energy away from seed production to flower production․ Most of the perennials will bloom a second time if they are deadheaded (cut down immediately after blooming)‚ and a few seed heads should be left on the plants over the winter months for birds and helpful insects․ By the end of February‚ cut everything back hard․
Dividing every 3-4 years․ This is the step people skip and then wonder why their hostas or daylilies stop blooming well․ If the roots are congested‚ dig up the whole clump in early spring or autumn‚ cut through with a spade into sections, and replant․ You will get free plants you can use elsewhere in your garden․
I take the time to understand shade
Multiple meanings exist for the term shade․ Failure to grow perennials that thrive under partial shade is the most common cause of unsuccessful shade gardening․ Partial shade means some direct early morning or late evening sun‚ but not during the heat of the day․ For example‚ on the east side of a house‚ or under a high tree canopy․ Full shade means little or no direct sunlight and only dappled shade․ It is usually found under reasonably large trees‚ often mature hardwoods․ In Tennessee‚ most large areas with tree cover are residential lots in the wooded foothills of East Tennessee mountains where full shade is the norm and not an exception․
Perennials That Actually Thrive in Tennessee Shade
Virginia Bluebells are flowers about 2 feet (0․61 m) high that form clusters of blue trumpet shaped flowers during the early spring․ They flourish in full or partial shade․ Do not be fooled; when their flowers are through‚ all the foliage dies back by early summer‚ so you will need to plant something to fill the space․ TN Nursery's Virginia Bluebell plants are a good choice if you want that genuine native woodland appearance․
Dutchman's Breeches is a true native rarity 2-3' tall‚ with strange pantaloon-like white flowers in the spring․ It prefers partial shade and moist soil conditions while actively growing‚ becoming dormant in the summer heat․ It doesn't seem to be the easiest plant to find either‚ but if you want something different from your neighbors‚ go for it!
The Great Blue Lobelia is about 3 feet tall and flowers in late summer when many other shade-tolerant perennials have already stopped flowering in June․ It really wants a wet‚ moist soil; it would work well in a soggy corner of a yard where nothing else will grow․ It tolerates more sun in cooler mountain spots than the hotter valleys of Nashville or Memphis, where afternoon shade is essential․
Red‚ purple‚ yellow, and pink‚ bell-shaped flowers grow on Columbine plants‚ which grow to 2 feet high․ Partial shade and moist‚ well-drained, and nutrient-rich soil is recommended․ They bloom from late spring to early summer․ It is also one of the more drought-tolerant shade perennials once established‚ and forgiving for a gardener who may not regularly check watering․
If you are making a whole bed that is going to be shaded‚ or just want to pick up some plants in bulk‚ TN Nursery sells a Shade Fern Package‚ which comes with many different kinds of fern to fill in around flowering perennials․
The Bottom Line
Growing perennials is not the fastest route to a garden․ But give them good soil‚ consistent watering in their first year‚ and a division every couple of years‚ and you will have a garden that actually improves with age instead of one you have to rebuild every spring․
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