Mulch - It Does a Plant Good

Mulch is an easy and cheap way to take good care of your plants.  Adding mulch is the simple practice of adding partially decomposed plant material, including wood chips, leaves, and other landscape waste, to your garden by spreading it in a thin layer on the surface of your soil.  Adding mulch to your garden is one of the simplest and most beneficial things you can do for your plants.

Mulch has many plant benefits.  As the cold weather draws near, adding mulch to your garden is especially important because it acts as an organic blanket, insulating the soil and protecting tender roots from cold temperatures.  Mulch also benefits your plants by maintaining soil moisture – with a good layer of mulch, soil surfaces are less likely to dry out under a hot, dry sun.  Mulch also suppresses weeds by reducing seed germination.  If that wasn’t enough, mulch also adds important organic matter to the soil.  As mulch further decomposes, it fuels beneficial soil microorganisms which help maintain healthy soils and healthy plants.

Mulch is cheap.  You can buy bagged mulch from your local garden center, OR you could get it for free.  There are a number of municipal recycling facilities on Long Island that pick up curbside leaves and other landscape debris and recycle it into mulch.   A number of towns give mulch away for free, including the Town of Smithtown Recycling Center and the Town of Southold.  Wood chips and fine screened wood mulch are available free to anyone who wants to come pick up a truckload.  Contact the Town of Smithtown Recycling Center at 631-360-7500 or their Kings Park location at 631-269-6600.

As simple and cheap as the practice of adding mulch may seem, there are also easy ways to mess it up.  The first is by applying the wrong kind of mulch.  Many “specialty” mulches are available including those made from recycled car tires and stone or marble chips.  These specialty mulches don’t decompose and don’t need to be replenished on a routine basis, but they also don’t add any of that super important organic matter to the soil.  They can even be harmful to plants by adversely affecting the soil pH. 

Photo: Mulch that was placed directly against the tree trunk up only six inches caused trunk rot and the formation of adventitious, circling roots on this Japanese Zelkova (Zelkova serrata).

But the most common problem I see with mulch is applying too much of it!  It looks like a lot of people went mulch-crazy and “too much of a good thing” was not in their comprehension.  Mulch that is piled up at the base of trees or shrubs, and that is 6, 12, or even 24 inches deep, is called a “mulch volcano” because of its similar shape.  In order to keep your mulch from “erupting,” you should place a thin layer only 2-4 inches deep on the surface of the soil.  Too much mulch may interfere with water penetration into the soil.  You should also be very careful to not place mulch directly against the trunk of trees and shrubs.  This is the biggest problem with mulch volcanoes because the constant moisture against the tree trunk can cause rot, be attractive to pests, cause improper root growth, and interfere with air exchange between the tree trunk and the surrounding air.       

Photo: On this properly mulched London Planetree (Platanus x acerifolia), you can see that the trunk flare is visible and not covered by mulch.

Adding mulch is one of the least expensive, easiest, and most beneficial practices in the garden.  Just make sure you follow the recommended guidelines, and remember, mulch – it does a plant good!

Freaky Science-Fiction Plants

Sunday night I was flipping through the channels and as always, there was nothing on TV.  As I grumbled to myself about the lack of good networking, one show caught my attention.  “Ladies and gentlemen – what he has created is new life itself – a completely new, synthetic species.  More with that story after these messages.  TICK TICK TICK TICK.”  What?!  Captivated, I stared at that incessant 60 Minutes clock on the TV screen, impatiently waiting to learn if the stuff of science fiction movies had actually come true.  Was Frankenstein created by some sick doctor that spent too much time at the Bodies exhibit?  Was DNA from the Jurassic Era discovered and a whole zoo of prehistoric creatures about to be unleashed?  Or did some crazy engineer actually design a conscious robot that could do all my house chores for me?  I intently watched the story unfold on the TV… 

Indeed – new life has been created.  A new species of single-celled bacteria, unofficially named Mycoplasma laboratorium, was created by the J. Craig Venter Institute in California.  The key thing about this new bacteria, is that it is completely synthetic – its DNA is totally man-made, and yet it is still capable of replicating all by itself.  Woah...  My mind reeled as I tried to grasp this incomprehensible new concept.  The lead scientist, Dr. J. Craig Venter, held up on the TV screen a yellowed Petri dish with tiny specks of black in it that looked more like mold than anything else.  And yet these tiny dots prove that humans are now capable of creating completely new life forms in a laboratory, simply by sequencing, synthesizing, and transplanting genomes – a feat that Dr. Venter called “miraculous,” right after he ironically denounced his belief in God.

60 Minutes explained that news of the miraculous discovery has reached President Obama, who recently held a meeting on the bioethical questions of Dr. Venter’s activities of “playing God.”  After the program was over and I got over the initial shock of the breaking news, I began to think…

Humans have been meddling with genes, shaping new plants, and “playing God” for millennia.  Ever since the dawn of agriculture, people have been selecting for certain plant traits and genes that are favorable to them – nutritional value or drought-tolerance for example.  Through this selection process, people have greatly changed the genetic makeup of plants that are useful to them.  This process continues today in food crops as scientists breed for the ability to be stored for extended periods of time on a grocery store shelf or for resistance to certain pests. 

In the realm of ornamental horticulture, plant breeders also “play God.”  By identifying individual plants with desirable traits such as uniform habit or flower quantity, breeders select for certain genes.  Most ornamental plants for sale these days are grown from cuttings - which means that they are actually clones of one another with exactly the same genetic makeup.  This guarantees that all the plants of a cultivated species will express the desirable trait. 

Perhaps the craziest genetic feat of ornamental plant breeders is that they have managed to develop new plants from two wholly different genera.  (If you remember, a genus is the taxonomic classification before a species.)  If you go to your retail nursery shop in the spring, you’ll see one of these science fiction-worthy plants – Foamy Bells (X Heucherella).  Foamy Bells were created by plant breeders who hybridized Coral Bells (Heuchera spp.) and Foamflower (Tiarella spp.). The intergeneric hybrid Foamy Bells would be like breeding a new animal from a domestic cat and a lion!

Photo: Foamflower is one of the parents of Foamy Bells. Above is 'Sugar and Spice' Foamflower (Tiarella 'Sugar and Spice'). 

Photo: Coral Bells is the other parent of Foamy Bells. Above is 'Citronelle' Coral Bells (Heuchera 'Citronelle'). 

Photo: Foamflower + Coral Bells = Foamy Bells. Below is 'Sunspot' Foamy Bells (X Heucherella 'Sunspot').

This photo courtesy of Missouri Botanical Garden PlantFinder. (http://www.mobot.org/gardeninghelp/plantfinder/plant.asp?code=B197)

Foamy Bells make great plants for a partially-shaded woodland garden with moist, well-drained soil.  They come in a never-ending variety of colors and their bold leaves add unique texture to the garden.  I guess we should blame all this meddling with genes on the Austrian monk, Gregor Mendel – if it wasn’t for his experiments with pea plants in the monastery garden, I’m sure the modern world would have no Foamy Bells. 

I don’t know what the upshot was or will be of President Obama’s recent meeting on the bioethical questions of synthetic bioengineering, but I am sure that Dr. Venter will continue with his synthetic bacteria research.  I’m also sure that plant breeders will continue to keep developing new, unique, and beautiful plants for the garden.  Dr. Venter says it’s only a matter of time before his synthetic cells give rise to new biofuels and pharmaceuticals...and maybe even conscious robots to clean the house too, which would be great especially around the holidays!  I guess we’ll have to wait and see… TICK TICK TICK TICK TICK



Is Fall Really for Planting?

It seems like all the plant nurseries have great big signs out now that say, “Fall is for Planting!” right next to their signs that say “50% Off Trees and Shrubs!”.  Fall is for planting mums, ornamental cabbages and kales, and spring-flowering bulbs, but is it really a good idea to plant trees and shrubs in the fall?  Who wants to be outside on a blustery fall day digging a planting hole while their fingers are turning blue?  Couldn’t it wait until the spring?

Photo: Early fall planting give roots ample time to grow before the following summer.

The idea behind fall planting is that trees and shrubs will get a head start on root growth before hot, dry weather comes the following summer.  With a larger root system, they will be better equipped to mine the soil for water than trees planted only a few months ago in the spring.  Long Island summers certainly have their fair share of droughts and heat waves, and lack of water is the most common cause of transplant failure, so this is a valid concern.  Yet some research has shown that fall planting is worse than spring planting or makes no difference.  So what are we to do?   

Provided you give your new plants enough water, you should be fine planting in the early fall, in September or October of a typical year.  But in late fall, in November or December when there may have already been a couple frosts, you should be careful planting the following plants:

·       Evergreens (especially broadleaf ones such as rhododendron or andromeda)

·       Balled and burlapped trees with a coarse root system

·       Extremely large trees (think 30 feet tall!)

The key to successfully transplanting evergreens in late fall is to make sure that they do not dry out over the winter.  Typically winter soil is wet because trees are dormant and aren’t using water.  But if a relatively warm day with bright sunshine and high winds comes along, the temperature of the leaf surface of evergreens can increase enough to cause transpiration and water loss.  If the soil is still frozen or even at a cold temperature that restricts water movement into the roots, the plant can suffer from winter drought-stress known as winter desiccation.  Evergreen leaves will turn brown and crinkle and may drop.

If you want to test your luck and plant evergreens in the late fall anyway, make sure to: 

·       Irrigate during a relatively warm winter day, especially when there has been no precipitation for a while and it will get cold again the next day.

·       Apply a 2-3 inch layer of mulch to insulate the soil and keep it moist.

·       Situate the plants in a non-windy location in partial or full shade (as long as they don’t require full sun) so that their leaves do not heat up as much in bright sun on a warm winter day.

·       Consider applying an anti-desiccant at the beginning of the winter and following up with repeat applications.

You should also be cautious of planting balled and burlapped trees with a coarse root system or extremely large trees in the late fall.  Some tree, such as oaks, naturally tend to have a coarser root system than others.  Very large trees will also tend to have a coarser root system.  This means that relatively few roots remain within the harvested root ball - the tree is more susceptible to drying out, and it has a smaller stored food supply which it needs to grow new roots and leaves in the spring.  (Trees store a lot of the carbohydrates they make during photosynthesis in their roots over the winter.)

Photo: 25 foot tall Littleleaf Linden trees were successfully transplanted in early spring in Southampton.

If you are still thinking about planting a coarse-rooted species or very large tree in the late fall, consider:

·        Planting a smaller-sized tree.

·        Planting a container-grown tree.

·        Planting a balled and burlapped tree that has been root-pruned to have a more fibrous root system during production.

So is fall for really for planting?  The answer is the most common answer in horticulture – it depends.  Know which trees and shrubs are risky to plant in the late fall, and think twice before you fall for some great end-of-season sales at the nursery. 

STOP Drop that fertilizer!

Fertilizers are not pesticides.  They are not toxic and are not meant to kill anything.  They can be applied without gloves and your dog could walk all over your yard directly after application without getting hurt.  Heck, little Rex could roll around in it if he wanted to!  Fertilizers are non-toxic and are composed of salts.  Just like people take supplemental nutrients in the form of vitamins, plants may also need to take supplemental nutrients in the form of fertilizers.  Essential macronutrients that plants need include nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.  Plants can’t simply eat a banana or drink some more milk to obtain their daily dose of vitamins – instead, they need to get their nutrients from the soil.

Photo: Everyone wants a lush lawn like this one in East Hampton

Some concerned citizen groups have eliminated the use of pesticides and fertilizers on their lawns and are advocating for others to do so as well.  If fertilizers are just plant nutrients, then what’s all the hype about?  Well, just like everything in life, a proper balance needs to be struck – not too little fertilizer, not too much fertilizer… just right.   A nutrient deficiency may cause a plant to have little or no growth, not photosynthesize properly, or be more susceptible to certain pest problems.  On the other hand, too much of a particular nutrient may cause a plant to grow too rapidly and decrease flowering, develop toxicity symptoms, develop other types of nutrient deficiencies, or be more susceptible to other types of pest problems. 

Too much fertilizer is certainly problematic for the plant, but environmentally-concerned people are worried about a much bigger problem - nutrient runoff and leaching.  If plant nutrients do not go into the soil and are instead carried off by rainwater, they can easily find themselves in one of the many bodies of water that surround Long Island.  Too many nutrients in the ocean, bay, or estuary is not good.  In very basic terms, what happens is that algae in the water quickly use the added nutrients and then multiply rapidly.  “Algal blooms” form which then deplete the levels of dissolved oxygen in the water creating a state of hypoxia.  Little oxygen is left for the fishes and shellfish and fish die-offs occur.  (Of course it is a bit more complicated than this, but you get the gist.)

So how do we find the amount of fertilizer that is just right?  The best way to do this is to take a soil sample and send it to the laboratory for analysis.  Soil tests are quite cheap and range from $15 - $65 per sample depending on how much information you want.  The other half of the story in protecting Long Island’s water bodies from nutrient loading is to follow the proper guidelines on how to fertilizer.  This includes applying fertilizer just before or when plant roots are actively growing.  Generally, spring and early fall is when the soil is warm and moist enough for plant roots to be growing and able to absorb nutrients.  But now that it is getting cold out, plants are preparing for dormancy and closing-up shop for the winter.  Both Nassau and Suffolk Counties have made a determined effort to protect Long Island’s water bodies from nutrient loading.  According to county laws, as of November 1^st, it is illegal for a landscaper to apply fertilizer to your lawn if you live in Suffolk County.  When November 15^th comes, it is illegal for a landscaper to apply fertilizer to your lawn if you live in Nassau County.  (Trees and shrubs are not included in these laws.)  The idea of these laws is to minimize the amount of fertilizer applied to turf grass when it is not actively growing or the ground is frozen.  April 1^st of next year, lawn fertilization can begin again.  Surprisingly, it is still legal for you to apply fertilizer any time of the year to your own lawn - you just can’t have the landscaper do it for you. 

Photo: Not fertilizing your lawn after Nov. 1st or 15th helps protect Long Island's water bodies like the Peconic River in Riverhead

So pack up your fertilizer for this season and when spring comes, remember that plants and the environment are like Goldilocks – they want their fertilizer just right.