Greetings!

The Macronutrients: Nitrogen

For the next few issues of the newsletter, I thought it might be useful to focus on the 3 main nutrients in fertilizers.  You know the old ratio, often written on the front of the bag.  A typical "balanced" fertilizer might be labeled at "13-13-13."  The first number on the label indicates the percent Nitrogen, the most important element in keeping plants healthy.

Nitrogen, Plant Macronutrient

Nitrogen is a macronutrient, which means plants need a lot of it.   Nitrogen is particularly important for the growth of leaves and stems, which means it affects the overall growth and health of the plant.  Symptoms of nitrogen deficiency are lack of vigor, slower growth, and yellowing between the veins of the leaves, which shows up on older leaves first.  Nitrogen dissipates quickly, which means it must be replenished frequently.

Conventional sources of nitrogen include ammonium-based products, which are inexpensive and readily available.  However, they are concentrated products which can burn if overused.  Organic sources of nitrogen typically also contain some phosphorus and potassium, and may come from animal sources, such as chicken litter or bird guano.  Cottonseed meals and dried molasses also contain nitrogen, but in far lower concentrations.  Organic nitrogen fertilizers are unlikely to burn your plants, but must be applied in higher amounts and sometimes with greater frequency.

Next time, we'll talk about phosphorus, another plant macronutrient. 

Wondering about your soil?  Papershell does soil analysis.  Download this fact sheet and stop by to pick up a sample bag.

Begonias: Beauty in the Sun or Shade

Wax begonias are among the easiest of our bedding plants to grow.  All begonias do well in bright shade, but the bronze-leaf varieties can also tolerate quite a bit of sun if kept moist.  Begonias flower from early spring right on through the fall, and respond well to periodic pinching back, for a full and lush look.  These begonias are annuals in our climate, though we are sometimes lucky enough to keep them through a mild winter or two.

Begonia 'Prelude Rose'

Most begonias get about 12" tall and 12" wide, making them perfect for low bedding or container plants.  Feed begonias periodically with fertilizers meant for flowering plants and water carefully: they're not especially drought-tolerant, but overwatering can lead to fungal problems.

Begonia 'Cocktail Whiskey'

Bronze-leaf varieties include the Party and Cocktail series, while Prelude and Olympia are green-leaf varieties, all in shades of pink, rose, red and white. 

Photographer Mark Grayden

Pest Patrol: Aphids

Aphids are tiny, sap-sucking insects that can inflict damage on ornamental plants, vegetables and fruits.  They are quite small and soft-bodied, appearing more plump than slender.  Aphids come in all different colors: clear, white, yellow, green and brown.  Usually they are found clustered together in groups.  They cause trouble several ways: by sucking vital plant juices, spreading virus and excreting honeydew, a sticky substance upon which sooty black mold grows.

Aphid

Generally, predator insects like red wasps will control aphids for you and you won't have to do a thing.  If it gets to be a problem, first try a high-pressure spray of water, plain or soapy.  Just blast them off your plant.  If you feel you must control aphids, look for the least toxic solution, which may be a Neem oil product or a horticultural oil spray.

Sooty Mold on Crape Myrtle Leaf

In our area, we probably have the most difficulty with crape myrtle aphids.  We don't notice the aphids much, but the black sooty mold that grows on the honeydew gets all over everything.  To control the sooty mold, you must first control the aphid.  For crape myrtle aphids, you may want to consider a systemic insecticide.  Systemic insecticides are selective because they only target insects that actually feed on the plant.  Use a root drench to limit the application even further.  That way, you won't harm bees and other beneficial insects.
 

Please stop by and visit!  The coffee's on us -- we'd love to meet you!

Sincerely,

Elizabeth Barrow
Papershell: A Garden Gallery