FERTILIZATION

The winter fertilization season should focus mainly on winter-hardy plants like trees, shrubs, and perennials. This season begins 4-6 weeks after the first killing frost and runs through early to mid-spring (until active spring growth begins), approximately December 1st through March 15th. Fertilization is intended to supplement naturally occurring nutrients in the soil, enhancing healthy growth and productive flowering and fruiting.

There are two main types of fertilizers, granular and liquid/water soluble. Granular fertilizers have a wide range of appropriate applications and are typically more economical and easier to apply. Many of the granular fertilizers we carry not only provide long-lasting nutrients but are also beneficial for microbial activity, which helps create a healthier soil environment. Liquid or soluble fertilizers are widely available but more complicated to use. They require accurate measuring and mixing before application. They are best used on crops such as annuals, vegetables, seasonal tropicals, and houseplants, especially during their active growing seasons. Liquid fertilizers are not generally recommended for use on trees, shrubs, vines, groundcovers, or perennials, especially in the winter months.

Trees and shrubs planted within the last year will benefit from a light winter fertilization applying only half of the usual recommended dosage. Choose a granular fertilizer with a low nitrogen percentage (6 or lower). Trees and shrubs in the ground for 1-10 years benefit from annual fertilization at the recommended rate with a balanced granular 6-6-6 fertilizer, or higher NPK ratio (not to exceed 20-20-20). Mature shrubs and trees (in the ground 10+ years) benefit from a balanced fertilization every 3-5 years tailored to their current health, desired growth, and site conditions.

Perennials can be fertilized anytime from early February to the end of March. Use a granular fertilizer and apply it evenly throughout the perennial planting area. An alternate and more aggressive fertilization plan would be to apply ½ the recommended amount of fertilizer in February then again in March and again in early June.

Ornamental grasses do not generally require fertilization at any point in the year and typically perform their best without them. Fertilization of groundcovers and vines is site, variety, and overall health-specific. Consult one of our team members for more information.

If you have plants that are in decline or have compromised health due to injury, insects, disease, or unknown causes please consult a professional before fertilization. We have Horticulturists on staff who can assist you.

PRUNING

Of the four seasons, winter is the best time to prune most plants. The winter pruning season begins only after several hard freezes. These hard freezes will take the plants into full dormancy. Full dormancy prevents any sensitive/tender new tissue or foliar growth from initiating and risking damage from cold temperatures. Waiting to prune until winter also allows you to see the structure of many plants, making pruning easier.

Deciduous plants, including trees and shrubs, are the main focus of the winter pruning season. It is recommended to prune Maples, birches, and yellowwoods in early to mid-winter before sap flow begins. Mid to late winter is the time to prune Roses, Annabelle and Panicle Hydrangeas, Crapemyrtles, Butterfly Bush, Abelias, and other trees and shrubs that bloom on new growth or are considered “cut-back” shrubs. Know what you are pruning before you prune because some plants set flower buds on old or last year’s growth, so if you prune at the wrong time, you may be removing the plant’s flowers for the year before you ever see them. The following is a list of blooming plants that should not be pruned in winter, prune instead right after flowering is complete: Azaleas, Lilacs, Forsythias, Oakleaf and Macrophylla Hydrangeas, Quince, and Viburnums.

Most perennials should be cut back annually in early winter. Some perennials are evergreen and don’t require cutting back or, if needed, should be done in the very early spring just before new growth or flowers emerge. It is important to note that some perennials have seeds such as coneflowers and rudbeckias which are an important food source for birds during the winter, so consider only cutting these back once the seeds are consumed. Perennials are a very diverse category with lots of variations for maintenance so please ask a team member for clarity if needed.

Most ornamental grasses can be cut back anytime from late November through mid-March. The exact time you cut these back is mostly determined by your personal taste. Cutting them back early will give you a clean look, but waiting until late winter will not only provide winter interest, but the dried grass blades and seed heads also provide an important food source for many birds throughout the winter. Some carex (sedge) varieties and small native grasses can be slow to reemerge after cutting back, so waiting until late winter into early March is best or not cutting these specific grasses back at all will give you the best results.

Groundcovers should be treated on a species-by-species case. One of the most common, Liriope, often remains evergreen most of the winter and can be cut back in late winter, before new growth begins. Ivy, Vinca, and Pachysandra are not typically cut back at all outside of maintaining boundaries. Vines are similar to groundcovers. Each vine has specific pruning needs with some never needing to be cut back. Please consult a Team Member for instructions on if, when, and how to prune your hardy vine.

Light pruning of most broadleaved evergreens, like hollies and southern magnolias, can be done in the winter. Pine, Spruce, and Firs (needled evergreens) generally require little if any pruning when placed in the landscape correctly. If pruning is needed, please consult a team member as a very specific time and pruning method is required.

When it comes to pruning plants to a controlled shape such as a hedge, cone, or topiary the best time to prune or shear is early summer after the new spring growth has hardened off. Pruning these types of plants in the winter is fine as well, but pruning in summer typically prevents them from starting to grow again, thus requiring additional pruning to maintain shape in the same year.

Pruning is both an art and a technical procedure. Improper pruning can be harmful to the plant in multiple ways and can lead to decline, weakened or excessive growth, and numerous other problems, so when in doubt always ask our professional Horticulturists.

EDGING & MULCHING

Defining bed lines and adding an insulating layer of mulch will help the sometimes barren, winter garden look tidy and fresh until the new growth emerges in spring. Edging and mulching can be done any time of year and may need to be done several times each year. Performing these tasks in the winter and again if needed in the summer leaves the busy seasons of spring and fall to other important tasks, such as planting.

It is important to maintain a clean-cut bed edge to reduce lawn grasses and weeds from encroaching into the landscape beds. It is also visually pleasing to have clean defined lines leading the eye around the garden. Avoid cutting the edge too deep as this can cause and encourage erosion not to mention a trip hazard. The edge should be just deep enough to mark and maintain the transition point from the lawn to mulched areas. For more information on tools and edging techniques please see a team member.

When it comes to mulching, our design philosophy at The Plant Kingdom is that the plants should be the focus of the landscape; therefore, we recommend using natural and neutral-colored mulches. All of the shredded mulches we carry are direct bi-products of the lumber industry and pine straw is a harvested product of pines grown for lumber. These mulches are readily available due to a lively lumber market and are considered environmentally friendly.

For most landscape spaces maintain a mulch depth of 2-3” for optimal weed suppression, moisture retention, and winter insulation. Mulching to a depth of 4” or more is not only more expensive but can be detrimental to your plants’ health. Never use fresh wood chips or bulk mulch that have not been properly composed. The natural chemical reactions assisting the necessary decomposition process will cause an environment that is not conducive to positive plant growth and can kill annuals and herbaceous perennials.

PLANNING

Start early and begin to plan small or large projects before the busy spring season arrives. Winter is an excellent time to be working in the garden and you can avoid the long lines or delays in service that occur each April and May. Ask a team member about our consulting services or visit plantkingdom.net/about and click on “Consulting & Design”. Want to be notified when a plant is back in stock? Try our popular notification request service. Stop in or send us an email to let us know what you are looking for.