There are many plants in the perennial garden that will either bloom continuously for 6-8 weeks (or more) or will go through cycles of heavy bloom, rest, and bloom again. This flowering takes lots of energy from the plants. You will notice a huge difference in the blooming power of your perennials if you do two important things: deadhead and feed them.
“Ever blooming” roses and daylilies are actually mislabeled. Both of these categories of plants are actually repeat bloomers. After the roses complete their first heavy flush of bloom, prune them back by at least 3-5 leaf nodes to an outside-facing 5-leaflet leaf. This encourages new growth to head away from the center of the plant. Use this opportunity not just to deadhead but also to shape the plant. Remove the spent blossoms of daylilies right down to the base before they have a chance to form seedpods. Both of these types of plants definitely benefit from a midsummer feeding.
Our Magic Formula for midsummer feeding is as follows: Put 3 bags of Coast of Maine compost in a wheelbarrow. Add 10 shovels full, approximately 1/3 of a 50 lb. bag, of Pro Start (a 2-3-3 blended organic fertilizer). Mix together until the fertilizer is evenly distributed. Add 1-4 shovels full of this mixture (depending on the size of the plants) to the base of all repeat blooming daylilies, roses, perennial salvias, butterfly bushes, and long bloomers such as thread leaf coreopsis, Kalimeris, Nepetas. You should also side dress heavy feeders such as Delphiniums that have been cut back to encourage a fall rebloom. YOU DO NOT HAVE TO FEED YOUR ENTIRE GARDEN if you have already fed the soil in the spring. This side dressing is an added boost for the plants that are going to go the distance for you in the late summer and fall.
Mid July is the cutoff date for pinching back fall blooming plants. By the time you are reading this, if you haven’t done your pinching, your plants will be very tall and leggy! Cut back Montauk Daisies, all tall asters, Helianthus, and mums, removing 1/4-1/3 of the top growth, thereby creating low-branched, full plants that won’t need staking. If you are afraid to do this, come in and let me show you on the garden walk.
Some plants will need a drastic chopping back after blooming in order for them to regenerate and form a new head of foliage and possibly even a new round of flowers for the fall. After Nepeta mussini has bloomed from late May until July, I pick up the lanky foliage with all of its unsightly seedpods and chop off its head to within 4-6” of the ground. I periodically deadhead perennial salvias, but when they get to the point that they are all stalk and no flower buds, I cut the flowering stems down to the base. Same goes with perennial bachelor’s buttons (Centaurea) and yarrows. This takes courage, but is worth it as these plants will regrow a new head of foliage and many will bloom again. After doing a drastic cutback, I always water the plants with a liquid seaweed/fish emulsion mixture to give them a boost.
The hotter and more humid it gets, the more important it is to foliar feed your plants. I always say that if we’re uncomfortable, so are the plants! Foliar feeding literally means watering the leaves with a dilute solution of some type of organic solution. I use a hose-end sprayer. It’s a quick job and produces fabulous results. If the weather is very hot and humid, or rain is lacking, I use Stress-X, which is an inexpensive soluble seaweed extract. Another alternative is to water your garden with Organic Plant Magic. Both have been proven to increase the plant’s resistance to stress and drought. For plants that have been drastically cut back or plants that need a nitrogen boost to green up their leaves (container plants being watered daily, butterfly bushes that are growing like weeds, delphiniums), I use Neptune’s Harvest Fish & Seaweed Fertilizer.
For roses, phlox, bee balm, Pulmonarias, and other plants stressed out and suffering from recurrent bouts of mildew, I use BioSafe Disease Control. How often do I foliar feed and what do I use when? I wish I could give you an exact formula. I use my instinct and I want you to learn to use yours. Monitor the weather and the conditions of your plants and keep in mind the basic guidelines above. We usually foliar feed every few weeks in a tough summer. You can’t make a mistake. No matter what you use, foliar feeding can only help.
The best way to control fungus is to head it off at the pass by spotting it when it first occurs and getting on a regular preventative spray program. Use BioSafe Disease Control as a preventative for fungus on plants it appears upon yearly. We preventatively spray our roses, phlox, bee balm, and Pulmonarias once a week.
Here’s the deal: water deeply. Period. Constant, shallow watering encourages surface roots and makes the plants much more susceptible to drying out (and tipping over in strong winds). If we have no rain, soak an existing garden once a week so that the water reaches deep to the root zone. Not sure if that’s happening? Dig up an area and SEE how the water has penetrated. Avoid watering in the middle of the day, as much of the water will evaporate. Don’t assume that using a sprinkler for an hour will do the trick—it really depends on how much actually soaks into the ground. We strongly recommend soaker hoses, as they conserve water, keep the water off of the foliage, and get the water to the roots, where it does the most good. Ask for our Water is Life handout for all the details.
In an effort to provide horticultural information, these educational documents are written by Nancy DuBrule-Clemente and are the property of Natureworks Horticultural Services, LLC. You are granted permission to print/photocopy this educational information free of charge as long as you clearly show that these are Natureworks documents.