NEIGHBORHOOD GARDEN FOR FEBRUARY 23, 2013

NEIGHBORHOOD GARDEN FOR FEBRUARY 23, 2013

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ACID LOVERS

BY GLADYS JEURINK

The soil around Lincoln varies just a little from neutral (7.0 pH) to usually just above neutral which makes it slightly alkaline. Plants have their favorite soils but so many times we want a non-native plant which likes acid soil. My soil usually reads about 7.2 pH and I wanted to have Blueberries which like it much lower (5.5 -6.0 pH) so I put them in large 20 inch containers so there would not be so much change needed. The fall before I added granular horticultural sulphur so it could dispense its influence all winter. Many recommend aluminum sulfate but you can easily get too much aluminum. So far I have eaten a few berries.

You have probably noticed there are very few Rhododendrons and Azaleas here in Lincoln. One reason is they like acid soil. Also they are shallow rooted and like a damp but not wet soil. This means you may have to water them in a dry winter as well as summer. If near the North foundation for the shade they like, the cement has alkali and lime dissolving off a cement foundation and a brick siding and then our soil changes back to its old high Ph so you need to acidify about every year. These plants have 4 needs.

1. Mulch to protect the shallow roots,

2. Acid soil,

3. Protection from wind and hot sun, and

4. Moist but not wet soil.

On my front lawn is a “Fringe Tree (Chionanthus virginicus) sometimes calls “Old Mans Beard”. It has bloomed several years but never had the blue berries so I must have a male tree. It has been covered with fragrant white flowers that hang down in slender petals like a fringe. My books say it will never be over 10 feet tall. Since it needs slightly acid soil I put coffee grounds under the tree and out to the drip line. They can be pruned as shrubs or small trees.

For those who like to grow their own Citrus fruit such as those small Oranges or Meyer’s Lemons, these plants like an acid soil.

There are acid fertilizers that can keep the pH to where it prefers, or a few spoonfuls of granular Horticultural Sulfur will do the same. They like regular fertilizing. The fruit may take almost a year from bud to eating so do not be impatient. Those blooms have a wonderful scent.

Hydrangeas have been work for a number of hybridists the last few years and a number of new varieties have appeared. Many of them prefer acid soils. Quite universal is the knowledge that on many Hydrangeas a pH of 5.5 or less produces blue flowers while soil pH of 6.5-7.0 produces pink flowers. It worked for me. I planted 2 Nikko Blue Hydrangeas about 6 feet apart, giving one sulphur and not the other one. The one in acid soil had gorgeous, huge blue blooms and the plant is still growing well. The other had pink blooms for about 2 years and then died.

Annabelle is probably the easiest Hydrangea to grow here in Lincoln. It spreads by roots every spring. The blooms are huge (12 inches). The new plants each spring are easy to move. My clump is probably 10 feet across and I have given many away. Just stick a spade under the baby sprouts, chop off the connection to the main plant, move it and keep it fairly damp for 2 weeks. You should have a new plant. I prune the entire plant to the ground each fall.

The vast majority of our favorite plants grow best in a soil that is only slightly acidic (6.2-6.8) which is easily done by cultivating beds with lots of compost. Pine needles are a good mulch as well as shredded Oak leaves. I like to shred the Oak leaves so they don’t blow away. If you don’t have a grinder you can run them through your lawn mower a couple times or shred them by hand. The Oak leaves won’t make any drastic changes but helps leave the soil to the acidic side. Canadian Sphagnum Peat Moss is also listed as acidic. I don’t like the fine moss as it tends to make a moisture proof cover if it is very deep and then dries out. The water runs off instead of going in so it needs to be well mixed with the soil when applied. Compost is more a neutralizer than a changer so I have come to believe you can seldom use too much and is also a good “food” source.

Holly is an acid Lover as well as needs some shade. Mahoney (sometimes called Blue Holly, prefers shade and acidic soil. Mine are on the east side of the house so gets only morning sun. Each spring I add sulphur and keep it well mulched. They do not demand a very acid soil so it doesn’t take as much as a Rhododendron or Azalea. I try to keep a pH of about 7.0. Holly cannot withstand drought so needs a little attention during a summer like we had in 2012. They are in the genus Ilex and many people call them “Winterberries”.

Holly are either male or female plants so you will need one of each to get a good crop of flowers and pretty red berries. One male plant can produce pollen for several females. When purchasing make sure the plants are labeled so you know if you are getting a male or a female plant. Getting a start from a friend is a gamble. You may get very nice plants, and they may grow and be pretty. Remember the male may have flowers but will not have berries.