Extension

The Winter Landscape

David Hillock

 

Winter can be a true test of the strength of a landscape design. With most of the landscape plants resting during the winter months, things of interest may be scarce. A key element in landscape design to sustain it year-round is the hardscape – those nonliving materials often used to establish the framework and backbone of the garden. A good hardscape will be pleasing, functional and provide interest during the winter months when many plants are dormant.

Hardscape materials include rock, pavers, concrete, wood, etc. These materials are used to create pathways, walls, fences, borders, benches, arbors, sculptures, and other structures. Using hardscape materials that are naturally found in your area, such as native stone, will help tie it into the natural surroundings. Using materials that are complementary to the materials used to build the home helps tie the home and landscape together. The landscape then becomes an extension of the home as well.

 

Many plants also provide interest during winter months. Evergreen trees and shrubs hold their leaves and colors year-round and contribute form, texture, and mass to the garden. Some deciduous trees and shrubs have interesting or colorful bark that can be seen easier and be more appreciated after the leaves have fallen. Plants with interesting bark include contorted filbert, red-twig dogwood, Japanese kerria, river birch, seven-son-flower, and oakleaf hydrangeas.

 

There are also several species that produce colorful or interesting fruits that persist into the winter months and may provide food for wildlife as a bonus. Plants that provide winter fruits include evergreen and deciduous hollies, coralberry, roses, firethorn, and Mexican buckeye.

 

There are even a few plants that produce flowers in winter or late winter/early spring. Witchhazels produce small flowers in January/February. Late winter/early spring bloomers include winter jasmine, winter honeysuckle, cornelian cherry dogwood, redbud, flowering quince, forsythia, and hellebores.

 

Herbaceous perennials may contribute to the winter landscape as well with their dried seed heads and interesting forms and shapes. Ornamental grasses are particularly attractive as they take on neutral colors and sway back and forth in the breeze.

 

As we move into the winter months, it is a good time to evaluate the landscape and identify its strengths and weaknesses. It is also an excellent time to work on the hardscape features of the garden. Need some inspiration? There are several excellent web sites, books, and magazines full of creative design ideas. These books and magazines make great Christmas gifts for the avid gardener in the family too.

 

Tool Cleanup and Sharpening

David Hillock

 

This is a good time to clean and sharpen tools before storing them for the winter. A little time now will ensure that they are ready to go as soon as it warms up in the spring. Shovels and hoes can be cleaned, sharpened at a 45-70-degree angle, and coated with oil to prevent rust. If the tool has a wooden handle, it can be coated with a layer of boiled linseed oil to keep it weatherproof. Tools such as pruners, loppers and saws should be sharpened professionally unless you have the proper equipment to sharpen them.

 

As mowers are put away for the season, one of the more important maintenance practices suggested is to sharpen that blade! Studies have shown that some of the problems we have with weakened lawns may not be due to environmental stresses but can be directly linked with failure to keep the mower blade sharp. A dull mower blade rips the grass, instead of cutting it cleanly. The ripping action makes a long, slow healing wound that makes disease invasion more pervasive. It can also lead to extensive tip dieback of the grass blade itself that reduces the effective photosynthetic area left to the grass following a cut.

 

Mower blades should be sharpened on a regular basis, and there is no better time to do it than as that mower is stored for the winter. This ensures that the first cut is a good “sharp” one!

 

Poinsettia Care

David Hillock

 

Newer cultivars of poinsettia, in addition to being very showy, have excellent keeping quality and stronger stems than older cultivars. When buying your poinsettia, choose a plant with well-expanded, well-colored bracts. Foliage should be medium to dark green with uniform coloring. Flowers should be present in the center of the bracts.

 

After you purchase your plant, do not expose it to chilling temperatures or cold drafts of air. If the temperature outdoors is below 50°F do not carry an unwrapped plant from the retail shop to your car. In the home or other place of display, avoid cold drafts and excessive heat from heating ducts, TV sets or large incandescent lamps. Temperatures of 70°F or below (down to 55°F) are desirable to retain best bract color. Large plants can be placed on the floor if light is adequate.

 

Light plays an important role in retention of leaves on the plant. Place the plant in an area where it receives at least six to eight hours of direct natural or artificial light. A minimum of 75 foot candles is desirable where possible. This would be like the minimum light intensity required for good desk lighting in an office. Incandescent lights such as those found in most homes will give a truer, brighter bract color than most types of fluorescent light.

 

Poinsettias can be displayed with other houseplants. The adjacent plants raise the humidity and allow poinsettias to last longer. Also, the regular houseplants can be spruced up for the holidays.

 

Many commercial growers use non-soil mixes of sphagnum peat, pine bark, vermiculite, perlite or similar ingredients. When plants are grown in such non-soil mixes, it is sometimes difficult to decide when the plant needs water. If there is no heavy component (sand or soil) in the mix and a plastic pot is used, the pot can be lifted to determine its weight. If the plant is heavy, there is usually plenty of moisture in the pot; if it is lightweight, the medium is dry, and a thorough watering should be given. Moisture needs can also be assessed by feeling the growing medium in the pot. Water when the top of the growing medium is starting to feel dry, but do not allow too much drying. Slight wilting of the plant is not harmful, but avoid severe wilting, which will cause leaves to drop.

 

Water the plant thoroughly. Make sure a small amount of water drips through the drainage holes of the container. If the plant is wrapped with decorative foil, punch a hole in the foil beneath the pot to allow excess water to escape. The plant should be placed on a saucer to prevent damage to the furniture or carpet.

 

Do not water the plant too frequently when the soil or growing mix is already wet or this may result in roots suffocating from lack of oxygen, causing the leaves to wilt, yellow, and drop.

 

Recent research has shown that poinsettias are not poisonous, but the plants are intended solely for ornamental purposes. Some people are allergic to the milky sap and may develop a rash when exposed to the sap. Avoid breaking the leaves and stems, as this will release the sap. It is wise to keep any houseplant out of the reach of small children and pets.

 

Houseplants in Winter

David Hillock

 

During the winter months our attention often turns to plants growing indoors. Like most plants outdoors, many plants indoors also go into a rest stage. This rest stage usually shows up as reduced growth and in some cases the loss of some leaves. This rest stage is a result of the shorter days and reduced light levels inside the home.

 

During this period plants won’t need too much water and little to no fertilizer. When a plant seems to be struggling most people tend to add more water or fertilizer, but this could lead to further problems. Unless your plants are growing under near greenhouse conditions, water only when the top ½ inch of potting soil is dry and avoid adding fertilizer.

 

Another problem that arises during the winter months is exposure to cold drafts or the dry, blasting air from the heater. Humidity can also be lower. To avoid these problems, locate plants away from doorways or the heater registers. Plants grow best at temperatures between 65°F to 75°F and a humidity of 50 to 60 percent. Temperatures are usually easier to control, but controlling humidity is more challenging. Humidity levels of 50 to 60 percent are higher than what most people like. Control humidity with a humidifier. A transparent polyethylene bag can be draped over plants that are extremely humidity sensitive or are in poor condition.

 

This is also a good time to see if plants are root-bound too. If they are root-bound, plant them in a pot that is only 1 to 2 inches larger in diameter than the pot in which the plant is currently growing.

 

Providing Adequate Light for Houseplants

Adequate water and light are the two most crucial requirements for growing plants indoors. Of these, light is usually the limiting factor, especially in rooms where outside windows are small, face the north or not present. Growing under lights relies on the intensity, quality, and quantity of light produced by fluorescent lamps.

 

Very few plants tolerate dark corners. Most houseplants require the light that would be found within four to eight feet of a bright south window. Some will tolerate a spot very near the window, while others will prefer less light some distance away. Too little light can result in tall, lanky, small-leafed plants. Too much light can cause leafburn on sensitive species like African Violet. Drapes should be left open during the day where houseplants are being grown; however, be careful not to allow the plants’ leaves to touch the glass of the window.

 

Properties of Light Intensity (Brightness)

Plants have different requirements for light intensity. Desert plants, such as cacti, require very high levels of light, whereas most tropical foliage and flowering plants require medium levels of light. Plants are generally segregated into the following categories based on their light requirement and intensity as expressed in foot-candles (ft c). One foot-candle is defined as the light produced by a single candle’s flame as measured at one foot.

 

Sunny or very high (>1000 ft c)

• Areas receiving at least 5 hours of direct sunlight in winter
• Window facing southeast, south, or southwest

 

Semi-sunny or high (500-1000 ft c)

• Areas receiving 2-5 hours of direct sunlight per day in winter
• Window facing east or west

 

Semi-shady or medium (150-500 ft c)

• Areas having bright, open light, but little or no direct sunlight
• Obstructed window facing east or west

 

Shady or low (<150 ft c)

• Areas receiving no direct sunlight, but having enough light to cast a shadow
• Window facing north

 

If the room is not naturally lit, artificial lights should be used. A 100-watt table lamp can be used about three feet above plants. Specially built fluorescent plant lights or plant flood lamps are available.

 

Fluorescent lamps are a good source of light for growing plants because they distribute light uniformly across the lamp and over lamp life. Plants can be grown very close to the lamps without heat damage. However, intensity rapidly decreases as distance from the lamp increases. Fluorescent lamps are usually suspended a few inches above the plant leaves. Light emitting diodes (LED) are fourth generation lighting sources and are an emerging technology in horticulture. Fluorescent, incandescent or LED plant lights are satisfactory for growing plants.

 

Quality (Color)

Plant growth lights produce most of their light in the blue, red, and far-red regions. Blue light provides energy for photosynthesis. Red and far-red light are important for flower initiation. Standard “cool white” fluorescent lamps produce light in the lower visible spectrum, i.e., blue to green to orange, and thus will satisfy the light requirements of many plants. Combining two of the plant growth lamps with two cool white lamps will provide good spectral distribution.

 

Quantity (Duration)

The intensity of light cast on plants’ leaves and the duration are important to the maintenance and growth of those plants.

• Seedlings require 16 hours of light per day
• Flowering indoor plants require 14-16 hours of light per day.
• Foliage indoor plants require 10-12 hours of light per day.

 

For more information see our fact sheet HLA-6411 - Houseplant Care.

 

Proper Pruners

Casey Hentges, Associate Extension Specialist
Bailey Singleton, Extension Assistant

 

Pruners are an essential tool for any gardener. When purchasing pruners, there are two main types: bypass or anvil pruners.  While this detail is often overlooked, there is a difference in what they do when used to cut a plant. 

 

Bypass pruners are typically the most commonly used pruner in the garden. They have a scissor like action where the cutting blade passes by another sharp blade, creating the cut. This leaves a nice smooth cut and does not do much damage to the plant tissue.  This is what makes bypass pruners the go-to cutting tool in the garden.  However, there are some limitations to this style of pruner. 

 

Because it has a scissor like action, when you try to cut something that is larger or harder, such as dead wood, the blades try to bypass one another. This often causes the blades to twist, which results in separation between the blades.  Doing this too often can cause your pruners to not work properly as it will create a gap between the blades – like that awful pair of scissors that may still be in the back of a drawer somewhere.

 

Anvil pruners are made specifically for the job of cutting larger, harder, dead wood. With a single blade that comes down, the plant tissue is squeezed onto the anvil, the blunt piece of metal or plastic.  This prevents any twisting and allows for more force to be applied to cut the branch. The branch is crushed between the two pieces of metal with this cutting action. Due to this, the anvil pruners are best suited for the removal of dead plant material and not ideal for use on live plant tissue as it can damage the remaining plant stems. 

 

Another option to consider is ratcheting pruners. Typically, these are anvil style pruners and are used for cutting larger, harder plant debris.  Without enough hand strength, regular anvil pruners can be difficult to use. Ratcheting pruners allow you to squeeze the handle, causing the ratchet to lock the blade in place. This allows you to squeeze again, cutting the branch.  Similarly, having telescoping handles allow you to easily cut through larger branches as well by giving you more leverage.  Additional they can extend your reach for larger shrubs and trees.  

 

For a more delicate cut, such as herbs or cut flowers, you want to look at getting a pair of snips.  Snips typically have long, straight blades that look more like small scissors than traditional pruners. With two sharp blades there will be minimal damage to the living plant tissue. This is important not only to the plant you are leaving in the garden, but in the part you are harvesting.  Snips are smaller and lighter, which allows you to get into tighter spaces and make more precise cuts.

 

While these are some of the basic styles, there are numerous brands, colors, and styles available.  One size does not fit all. They are made in different sizes because people have different sized hands. There are also other features to look for. Some have a serrated upper portion on the blade for cutting rope while others have a little notch inside the blades to cut wire. 

 

Garden pruners have very specific roles in our garden. Using the proper pruner for the job will ensure you and your plants the most success this season.

 

Find more information about pruners on the Oklahoma Gardening YouTube channel.