Maintenance
It is important to take care of your landscape investment: by pruning trees and shrubs, and taking care of disease and pest problems quickly.
Dead Heading
Some perennials and annuals re-bloom if their spent blooms are removed or cut back - this is called 'Dead Heading'. Once a plant makes a seed after blooming, it thinks that it has done its job, and stops blooming. Dead Heading is a way to 'trick' the plant. However, some plants will not re-bloom (such as Peonies, Irises, or Liatris.) Dead Heading also keep the plants more attractive, and can prevent disease (like in peonies). It can even cause the plant to become bushier, less floppy and can also increase the number of flowers. Of course this all depends upon the particular kind of plant.
Weed, Insect & Disease Control
Should be addressed before planting, or it may become a problem again in the future. Creating a new planting bed stirs up the multitude of weed seeds lying dormant in the soil, and they may germinate and grow. Pre-emergents applied to the soil help to make sure that this doesn't happen. Most perennial weeds that are already in the bed have deep roots and need to be sprayed with a non-selective herbicide, or they will come back from any portion of the root that is left if they are pulled out. Mulch helps to keep down the weeds also.
Fertilizing
Feed your trees & shrubs anytime from late fall to early spring, starting the second year. Trees that are fertilized may have 2-3 times more growth then those that haven't. Cypress Group, Inc. applies fertilizer to planting holes and beds. Perennials should generally be fertilized in the spring when they are starting to emerge. Native plants can become too floppy and tall if fertilized. A 10-10-10 fertilizer works well.
Pruning
When you prune is as important as if you prune. Flowering shrubs form their buds after they bloom. If you prune them after the buds have formed, you are cutting off next year's blooms.
Removing broken or diseased branches or foliage is important, so that disease and insects won't be attracted. Trees with a single trunk should only have one leader or main branch. Sometimes additional leaders will form, that need to be removed.
Fall Clean-up
If you are a neat-nick, you will want to remove the leaves in your planting beds in the fall. Leaves should be removed from your lawn, as they can smother the grass during the winter. However, leaves in your beds are not always a bad thing - as they decompose, they become mulch, and provide nutrients to the soil. They also can help to protect perennials and roses in the winter. Tougher or larger leaves may need to be chopped up to aide in decomposition (a mower works great for this - bag it, then you can dump it where you want it).
To cut back or not to cut back ornamental grasses? That is the question. Do not cut back ornamental grasses until early spring, as the foliage provides winter interest and homes for wildlife, and also prevents crown rot. Plants that are prone to disease, such as Peonies, Iris, Daylilies, etc. should be cut back. Plants that don't retain their shape, the foliage dies to the ground, or flop excessively in the winter (like Hosta) should be cut back. Some plants have seed heads that wildlife and birds love and need to survive the winter (like Coneflowers). These seed heads or berries can add great beauty & interest to the barren winter landscape. Zone-hardy Roses (like Knock Out or Flower Carpet) should not be cut back until they start to bud out in the spring. They die back from the tips, and if they are cut back severely, they can die back to the roots.
Summer Maintenance:
Check your beds regularly for disease and insect infestations. Remove or spray weeds promptly. Reapply pre-emergent to the beds as recommended by the manufacturer. Remove spent flowers (dead head) if you want many of them to rebloom.
Dead Head
Certain perennials will re-bloom if dead headed monthly. Here are some common plants that we use that benefit from dead heading: Bee Balm (Monarda), Black-Eyed Susan (Rudbeckia), Bleeding Heart (Dicentra), Butterfly Bush (Budleia), Catmint (Nepeta), Coneflower (Echinacea), Coreopsis, Daylily (reblooming types), Dianthus, Phlox paniculata (not creeping type), Roses (many kinds), Salvia* (perennial), Shasta Daisy (Leucanthemum), Spiderworts (Tradescantia), Veronica spicata* (upright kind), Yarrow (Achillea)
* These plants have spike-like blooms that open from the bottom to the top. Remove them when the spike is 70% finished blooming.
How to dead head: the first time, cut off the bloom to the first bud or leaf. Then the second time, dead head it to another lateral flower or bud, and so forth until there are no more lateral flowers or buds left. Then you can cut off the entire stem back to the basal foliage. For plants that grow on single, bare stems like Lanceleaf Coreopsis, just grab a handful of spent blooms and cut them off. If you are really adept, use garden shears - it's much faster. Perennial Geraniums are tough to trim individually, so cutting back to 4-6” can help encourage new growth and blooms.
Other plants that will not re-bloom, still can benefit from dead heading, because it just makes the plant look neater, or it keeps them from forming a seed pod, that takes energy away from the plant. Examples are: Lady's Mantle (Alchemilla), Brunnera, Coral Bells (Heuchera), Hosta, Iris, Lilies, Daylilies (that aren't rebloomers), and Lungwort (Pulmonaria). Lastly, some seed pods can reseed - which can be messy, or not produce plants true to the originals: Black-eyed Susan, Caryopteris, Butterfly Bush, Rose of Sharon (older cultivars), Salvia, Sedum, and Yarrow.
Some plants are prone to disease, and removing spent blooms help to curb this (like Peonies).
For plants that product lots of small blooms, it is easier to use scissors to shear them off (such as Catmint, Dianthus and Threadleaf Coreopsis).
Certain annuals (like Coleus) become bushier, or re-bloom better (like Snapdragon), when dead headed. This is very important in container plantings, as you want them looking great all summer. Pinching back is very important to keep some plants in control and re-blooming.
Cutting Back
Some plants benefit from being cut back in the spring to one-third, to one-half to control height and form later in the season: Rose of Sharon, Aster, Coneflowers, Lobelia, Phlox (Tall Garden type), Obedient Plant (Physostegia), Black-Eyed Susan (Rudbeckia), Sedums (tall types), and Veronica. Some plants like Spiderwort (Tradescantia) or some Salvia start to look ratty in mid-summer, and they can be cut to the ground to start over.
Be careful not to wait too long to cut back, otherwise you may be cutting off next year's blooms.
Some plants that have bulbs or bulb-like growths, it is important not to cut back the foliage as it dies, as it continues to provide food for the bulb (like Lily, Daffodils, Tulips).