Perennial Maintenance


January, early February:
1)   In February, remove any old stems or dad leaves from plants.
2)   Pull or hoe any winter weeds.
3)   Throw handfuls of a balanced fertilizer out, sparsely, all over the beds.  Avoid getting it in crowns of plants.  Set the sprinkler on and water well to wash off any granular fertilizer that may be on the leaves.  Do this when plants have not yet, or are just beginning to come out of dormancy and begun to grow.
4)   Divide anything that seems to coming up too large for its place.
5)   Apply an organic much.

March, early April:
1)   Look for seedlings that have sprung up out of place, like ruellias, gauras, verbena and pestemon.  Move to a more appropriate place while plants are still tiny, taking a chunk of soil with the seedlings.  Water well.
2)   Watch for out-of place plantlets from plants that propagate by underground runners, like yarrows, and tall ruellias.  Detach rooted runners and move to more appropriate place.
3)   Divide gingers, move small banana shoots. 

June 1st:
1)   Cut Phlox and obedience plant down to 1 ft. from the ground to cause branching.
2)   Dead-head all spring bloomers, removing flower stems all the way to the ground.
3)   Cut back by half dianthus, candytuft and moss phlox.
4)   Weed.  Apply ‘Sedgehammer’ herbicide to purple nutsedge.  Use specific grass killer herbicide on Bermuda grass.  Spraying is more effective that grubbing out these tough perennial weeds.
5)   Recut border edge with a sharp edging tool.
6)   Begin regular watering to encourage rebloom of daylilies and crinums.
7)   Cut hollyhocks nearly to the ground to encourage perennialization.
8)   Evaluate the overall look of the border.  Mark anything that seems out of place for moving in November.  Place tall plants in back, mid-size in middle, short in front.  Its okay for medium height plants to come to the front, but not for tall plants to grow in front of shorter ones.
9)   Mark daffodils and other bulbs that you intend to divide, before the foliage completely disappears. 

July 15th:
1)   Cut down Asclepius (butterfly weed), and pentas to 1 ft. tall to cause branching and rebloom.
2)   Cut down swamp sunflower, forsythia sage and other tall salvias, mums and obedience to 1 ft. tall to cause branching and avoid flopping.
3)   Cut back artemisia and salvias to 1-2 ft. to encourage branching.
4)   Deadhead stems of all plants that have finished blooming.
5)   Weed, check for nutsedge and Bermuda and spray again if needed.

August 15th:
1)   Cut down Rubeckia by 2/3 to encourage blooming on lower parts of stem.
2)   Divide Louisiana and bearded irises, reset and keep watered.
3)   Cut back roses to around 2 ft. tall to encourage fall bloom.
4)   Remove all finished bloom stems.
5)   Recut border edge.
6)   Reapply organic mulch.

September 15th:
1)   Cut down rudbeckia Goldstrum after blooming to encourage rebloom.
2)   Divide and replant narcissus bulbs if you can find them.  If you wait till later, they will have formed roots and be stressed by moving.
3)   Weed, check for nutsedge and Bermuda and spray again if needed.  Cut and remove any turf that has crept into the periphery of the border.
4)   Divide calla lilies, before temps cool off and they begin to leaf out again.

November 1- December 15th:
1)   When day temperatures cool, begin dividing perennials.  Enrich the soil with manure or other organic matter before replacing plants.  Water in well after replanting.  Break apart easily divisible plants like mums, shastas and rudbeckias.  Daylilies that are very overgrown may need to be forced apart by back-to-back spading forks.  Very vigorous plants that make underground runners, like some rudbeckias, yarrows and oenotheras only need a single division replanted, rather than a clump of plants.  One plantlet will fill the space.
2)   Move everything you’ve marked as being out of place during the hot season.  Make all major planting changes now.
3)   Water the border at least once during winter, very deeply, so that plants can survive any hard freezes without difficulty.  Resist the temptation to ‘neaten up’, as old plant parts will protect crowns from freezing. 

Denyse Cummins, Area Hort. Agent
NW Horticulture Office of the LSU AgCenter
3101 Fairfield Ave., Shreveport, La. 71104