Treat Yellowing Leaves on Broad-leaved Evergreens

Are your Camellias or Hollies showing yellowed leaves this time of year? Some leaves are naturally aging and yellowing. Other plants with yellowed leaves have a condition known as chlorosis and may include Pieris, Illicum, Rhododendron, Camellia, Ilex (Holly), Gardenia and other broad-leaf evergreens. The yellowing is typically due to one of two causes. The plants may need a Nitrogen fertilizer or they may need the application of the micronutrient Iron. 

This yellowing of foliage or chlorosis can also occur in potted houseplants such as Citrus, Ficus and Jasminum. 

How to tell?

CrabappleLandscapExperts will examine the plants carefully.

Nnitrogen Deficiency, Flordia.edu

Nitrogen Deficiency

When a plant lacks the macro-nutrient Nitrogen, older or lower leaves will yellow uniformly and often drop. The plant will transfer available nitrogen to its growth tips and new leaves.

Nitrogen Treatment

The LandscapExperts add Nitrogen by adding organic sources such as compost, well-rotted manure, fish emulsion, or commercial fertilizers. Water-soluble fertilizers designed as foliar feeders are easily mixed and sprayed onto the foliage. We also ensure that adequate Nitrogen fertilizer penetrates the soil and root ball. Our mixtures that are high in Nitrogen, denoted by the first number in the formula. The LandscapExperts always follow the directions for application to avoid over-feeding that can damage plants.

Iron Deficiency, Cornell.edu

Iron Deficiency

On the other hand, Iron deficiency symptoms are first expressed in the new growth or young leaves. Iron-deficient leaves show a characteristic inter-veinal chlorosis, with the leaf blades turning pale green to yellow, but the veins remaining dark green. Iron deficiency often goes along with Zinc and Manganese deficiencies, and these are all micronutrients that plants need for good growth. The new leaves are not producing enough green chlorophyll because of the lack of the essential micro-nutrient, Iron, which is a component of the chlorophyll molecule.

Iron Chelate Treatment

Iron Chelate (pronounced KEY-late) is a nutritional supplement that provides a soluble source of “liquid iron” that is immediately accessible to plants. It is commonly used as a foliar spray to treat the symptoms, and provides quick and easy correction of iron deficiencies. The leaves typically green up in less than a week! Liquid Iron is chelated iron with copper, manganese and zinc. A small amount goes a long way, particularly for potted plants -- only a 1/2 teaspoon per quart of water is advised.

Fast-acting Iron Chelate is often mixed with seaweed and other organic formulations as a broad spectrum tonic for plants. Repeat monthly. It aids in the production of vigorous dark green plant growth and corrects micro-nutrient deficiencies.

Shape-up and Re-pot Leggy Houseplants

Spring arrived at 7:02 am ET today, Thursday, March 20!3! We say Welcome! 

Late Winter / Early Spring is the perfect time to re-pot and shape-up leggy houseplants that have survived the winter indoors. Crabapple LandscapExperts can also advise you on how to care for large display tropicals inside the Sales Office or Residents' Clubhouse.

Pinching, Pruning and Shaping

Many houseplants need regular pinching back to keep them shapely. These include coleus, grape ivy, Swedish ivy, philodendron, arrowhead plant, polka-dot plant and wandering Jew. Houseplants grown as a topiary or on a topiary frame also need frequent pinch training.

Others need regular pruning once a season to maintain their appearance and vigor, keeping them compact, dense and healthy. Lipstick plant, for example, benefits from pruning back a third after flowering while Columnea is pruned in Spring to encourage re-flowering. 

Still others like Ficus benjamina, Fittonia and Pilea may need the removal of dead or crossed branches or damaged wood.

Vines such as Pothos produce trailing stems that can become lanky and leggy, with long gaps between the leaves, particularly in conditions of low light. Pinching the growing tips just above a leaf node will encourage the plant to put out new stems and bushier growth.

Grooming 

Grooming is a good idea for all houseplants, and consists of removing yellowing or dead leaves for an improved overall appearance. To encourage even growth, rotate houseplants by a window a quarter turn each week, causing them to adjust to the source of light in the room.

Is Repotting Needed? Indications: 

Roots growing out of the drainage holes at the bottom of the pot

Water runs down the sides and out the bottom without soaking into the soil

Top-heavy plants that fall over

Plants are straggly, pale, and have stopped growing

Thick roots circle around inside the pot

Repotting

Late winter / early spring is the ideal time to replant houseplants, since it is just prior to their spring growth spurt. Water the plant then gently remove it from the pot and lay it on its side.  Inspect the roots and soil.

Larger Pot 

For a larger plant, gently tease the roots apart and repot in a larger pot. Trim off dead or rotting roots at this time.

Place fresh soil in the bottom of the pot in order to keep the root ball at the same level, then place the plant in the pot and settle it, making sure it is centered and upright. Add potting soil around the sides, pressing down to firm the soil. Water in thoroughly.

Same Pot with Root Pruning

To keep the plant the same size, root prune by shaking off excess soil, and then using either utility scissors or a long, serrated bread knife, reduce the root system an inch or so all the way around, up to 25% of the root ball. Clean the pot by scrubbing with a 10% bleach/water solution, rinse, dry, then re pot the plant in the same pot with fresh soil. 

Light Maintenance

For light maintenance, simply top dress by scratching up the surface of the root ball before refreshing the top layer with fresh potting soil, but make sure the top of the root ball remains about ½ inch below the pot rim to accommodate watering.

Quick Recovery

Repotted plants will need a few weeks to recover from repotting, so water regularly, hold off on fertilizer, and keep the plant in a brightly lit location, but not direct sunlight. 

CrabappleLandscapExperts advise commercial and residential managers and HOAs that interior plantscaping:

adds to a feeling of well-being,

reduces stress indoors (and out),

improves air quality by increasing oxygen and humidity and decreasing carbon dioxide dust motes

reduces background noise 

Schedule Spring Core Aeration for Warm-Season Grasses

Creeping, warm-season turf grasses such as Bermudagrass and Zoysia  are particularly inclined to build up a layer of thatch. Thatch is an accumulation of dead leaves, cut grass clippings, dead roots and miscellaneous debris. It settles at the soil level of the individual grass plants that make up a lawn and prevent water and nutrients from reaching the roots. Crabapple LandscapExperts recommend Core Aeration as the best way to counteract thatch. 

Hollow tines in Aerator

What is Core Aeration?

Core aeration is the removal of small cylinders or “cores” of soil from compacted lawns (especially those with a layer of thatch), creating spaces that allow the rain and fertilizer applications to soak into the root zone and the roots of the turf to breathe and expand. The hollow tines of an aeration machine pop out ½ inch diameter tubes of soil about 3-4 inches long, and deposits them on the lawn where they soon dissolve.

Spring is Ideal  for Core Aeration of Warm Season Turf  March through July

Your Crabapple LandscapExperts Rep can evaluate your turf and recommend this procedure if needed. Some indicators include: a thatch layer thicker than ½ inch;  underlying soil is heavy clay; the lawn is heavily used causing thin areas; or if the turf is only shallowly-rooted.

The best time to Core Aerate a Bermuda or Zoysia lawn is March through June/July when warm season grasses are emerging from winter dormancy and beginning a vigorous period of growth as the soils warm up. Maximum benefit and fastest recovery occurs when lawns are aerated at this time.

Core aeration is not recommended on newly-seeded lawns. For complete details contact your Crabapple Rep today to schedule this beneficial horticultural practice and improve the growth and look of the lawns on the properties you manage. 

Digging Deeper

See Crabapple's other blogs on this important topic: 

http://crabapplelandscapexperts.blogspot.com/2011/03/top-10-benefits-of-core-aeration-to.html 

A Link to Crabapple's Video on Core Aeration: 

http://www.youtube.com/watch?v=gmTKyw1TZb0&feature=email

Don't miss any of the new  short landscaping demos and best practices on the CrabappleLandscape YouTube Channel. Subscribe now to be notified when a new video comes online!

Lichen on Tree Bark - indicates good air quality

Leafy-looking lichens on tree bark, photo from NZ.

Have you wondered about turquoise or pale gray-green, leafy circles on your tree trunks? These are lichens. 

CrabappleLandscapExperts know that lichens only grow where the air is relatively pollution-free, and their presence is a good sign—an indication that the air in your neighborhood is pretty clean! When an area is polluted, lichens will become scarce and eventually stop growing.

What are lichens?

Not a moss, not a mushroom, lichens are dual organisms, composed of two species living together in a mutually beneficial symbiosis.

One of the species is a fungus, which adheres to a substrate and absorbs water and mineral nutrient for the algae. The other species is an algae or a cyanobacterium (blue-green bacteria)  (or occasionally all three together) which uses water and carbon dioxide together with the energy of sunlight to photosynthesize and produce food for the dual organism. Quoting Trevor Goward, "Lichens are a case of “fungi that have discovered agriculture”.

Lichen circled in photo by PA-CES

What do Lichens look like?

Lichens are often turquoise or pale gray-green having a vegetative, leafy-like organ that grows outwards in a circle and is called a thallus. They attach themselves to undisturbed surfaces: Lichens often grow on unfinished wood surfaces, boulders or tree bark. Lichens are often viewed as making a tree more picturesque. Most people don't mind having lichens on their tree's bark because they can add color, contrast, texture, and natural beauty to the landscape. There is no reason to remove them, and the tree bark could be damaged in the attempt.

When the Japanese Garden of the Atlanta Botanical Garden was refurbished, disturbed lichens growing on the carefully-selected and -placed boulders were skillfully "touched up" with latex paint to preserve the aesthetics. 

Rugged bark with lichens, photo from WikiCommons

Lichens cause no damage

Because they make their own food with sunlight and water, lichens are not parasitic and pose zero threat to the health of the tree, or to you and your family.

Best Conditions for Lichens?

Lichens are found on every continent including the Arctic and Antarctica. Lichens on trees grow best in cool, partly sunny, moist locations. Thinning out tree branches overhead to allow more sun and air flow will help, as will occasionally “watering” lichens with a sprinkler system.

Ecological Roles and Economic Benefits of Lichens

• Lichens act as early colonizers that re-establish life on bare surfaces like rock and boulders 
• Lichens help regulate the composition of gasses in the earth’s atmosphere. Each lichen acts as a “sponge” to catch and store excess gasses like carbon dioxide, thus filtering the air we breathe. 
• Some lichens (those in symbiosis with cyanobacteria) have the ability to return valuable nitrogen to the soil, somewhat like legumes changing atmospheric nitrogen to plant-available nitrites and nitrates 
• Source of dye for wool, fabric, textiles,  particularly craft dying 
• Antibiotic properties act as a healing aid to superficial wounds 
• Used fresh or dried in floral designs 
• Used as a bitter flavoring for beer in Siberian Monestaries, in fermented corn beverages in Mexico; for flavoring by Swedish brandy distillers 
• Caribou / reindeer graze on lichens in northern tundra regions

Your LandscapExpert is happy to answer questions about the natural world.  

Digging Deeper

10 Things To Know About Lichens http://ohioline.osu.edu/sc195/029.html

Lichen website http://www.lichen.com/

Even more about lichens http://www.lichen.com/biology.html