Herself's Houston Garden

Conservation through cultivation

Archive for the ‘tree’ tag

Trees retaliate when their fig wasps don’t service them

without comments

It would seem trees are not as dumb as they first appear. When wasps try to lay eggs from outside the flower with out pollinating the flower, instead of inside the flower while spreading pollen the trees drop the fruit containing the baby wasps to death.

While trees often drop unpollinated flowers, they will often hold onto the galls containing the wasps and provide themselves with a future generation of pollinators.

Figs and fig wasps have evolved to help each other out: Fig wasps lay their eggs inside the fruit where the wasp larvae can safely develop, and in return, the wasps pollinate the figs.

But what happens when a wasp lays its eggs but fails to pollinate the fig?

The trees get even by dropping those figs to the ground, killing the baby wasps inside, reports a Cornell University and Smithsonian Tropical Research Institute study published in the Proceedings of the Royal Society B (published online Jan. 13). ( read more read more about tree retaliation )

More information
Abstract
Download the paper (pdf)

Written by Linda MacPhee-Cobb

February 17th, 2010 at 8:00 am

Posted in plant science

Tagged with , , ,

How to prune your fruit tree in 5 easy steps

without comments

Fruit trees need frequent proper pruning to reach their full potential.  You’ll want to spend some time once a year, after the fruit finishes and before the new buds appear to give your tree a serious pruning, but don’t let water spouts or crossing branches stay when you find them.

Remember when pruning to step back and circle the fruit tree frequently to see how it looks while you are working.  You want a slighly domed shaped top, and the bottom should look like a steep bowl.

1) Remove water spouts.  Water spouts are branches that grow at 90′ angles to the branch they stem from. They will take all of the nutrients and water away from the rest of the branch if you let them grow.

2) Remove all branches that bend down toward the ground.  Your branches should curve or reach up not down.

3) Remove all branches that cross another branch.  On windy days those crossing branches will rub each other.  This causes breaks in the bark where insects, fungus and bacteria can enter and harm your tree.

4) Thin branches so that sunlight reaches deep into the tree.  Fruit trees especially need lots of sun to grow well and remain healthy.

5) Shape the top just for appearace, cut back to the beginning any branches that stick out too far from the rest.

The branches you remove can be used to propagate new trees.  Cut the branches so that only 3 sets of leaves remain.  Remove the bottom set of leaves.  Dip the bottom of the branch in rooting hormone.  Plant in light soil and keep warm, moist and humid until new growth appears.  Then treat as you would any other young tree.

Written by Linda MacPhee-Cobb

March 11th, 2009 at 8:49 am

Coral Bean Tree aka Fireman’s Cap ( Erythrina x bidwillii )

without comments

I first heard about Fireman’s Cap at a lecture I attended for under used plants in Houston. This plant is a hummingbird and other bird attractor. They can’t resist those bright red flowers.

Blooms appear late spring, mine started late May this year. It should bloom through out the summer now. Flowers appear first followed by leaves.

It will reach about 8′ tall with a 5′ spread. Fireman’s Cap can go as high as 20′ tall with a 10′ spread. It is fast growing. I stuck this sorry looking one foot tall twig in the ground in March and you can see how large it is the first of June. It is very fast growing, the branches are almost vine like when they first appear, soft and rapidly reaching for anything.

It prefers full sun, but will accept part sun. So they say, however I found mine did much better in part shade than it did in full sun.

Watering needs are average to low, drought tolerant once established. It wasn’t the least bit bothered by the 6 week spell of hot, dry, windy weather we had a few months back.

Be careful where you plant it, the thorns are impressive. You don’t want to have to be pruning it often.

This is a cross between E. crista-galli which is a member of the pea family, and very much like the Fireman’s cap but is not frost hardy and E. herbacea ( Cherokee bean ) which has bright red tube like flowers and is more woody than e. crista-galli.

Seeds are reportedly sterile. It is very cold tender and will drop its leaves and may die back to the ground in colder winters.

Awarded the Merit award by the Cal. Horticultural Society in 1981.

Poisonous do not eat it.

If possible protect from wind and also from hard freezes. Go easy on the fertilizer in the fall to help it prepare for winter but don’t underwater. This one died back to the ground after several hard freezes last winter, but re-appeared mid May 2010.

Propagate by seeds or cuttings.

Cutting propagation:
Remove a new growth that is just beginning to get woody that has at least 3 sets of leaves.
Remove the bottom two sets of leaves.
Dip the stem in rooting hormone powder
Plant in moist soil covering the stem where the two bottom sets of leaves were removed. Using lots of peat moss in your soil helps keep fungus down.
Keep in a moist place and keep soil damp.
Be sure to remove air spaces between stem and soil as these tend to get moldy.
Do not let stem touch bottom of pot. It should have an inch of soil below it.

Note: Survived the great heat and drought of summer 2011, no blooms yet.

Written by Linda MacPhee-Cobb

July 31st, 2008 at 5:00 am

Tips for tree planting in Houston

without comments

Trees can be planted or moved any time of year provided . . . you are going to remember to go out and water them almost daily if we have no rain. If you are not going to go check the soil around your new tree every day for a year, plant it in Dec/Jan/Feb when it is dormant and we are getting plenty of rain.

Do not fertilize your tree the first year, except for the local preferred starter ‘SuperThrive’. I myself prefer Shultz ‘Starter Plus’ which just has extra phosphate to get the roots growing. Only use these once when you first plant the tree. After that wait a year before fertilizing.

When you move a tree remember you must remove equal amounts of leaves as you have roots. If you left half the roots behind, you had better prune off half of the leaves. If you purchase a tree for planting don’t do any pruning the first year.

Dig a hole twice the width of the root ball and about as deep as the root ball. You don’t want the tree settling down into loosened soil underneath it.

If it is a potted tree you purchased, unpot it and cut off the very bottom of the root ball. Then slice four vertical slices about a quarter inch deep down the root ball. Do these an equal distance apart with a razor or extremely sharp knife. This gets the roots growing in a direction outside the shape of the pot.

Place the dirt and the tree in the hole so the tree ends up with its base just a few inches above ground level. Cover the ground with a couple of inches of mulch for at least a foot, maybe two around the tree.

Now take your left over dirt and create a wall around the mulch a couple of inches tall. This helps keep water in near the roots of your new tree and helps prevent injuries from lawnmowers and weed trimmers.

According to the A&M, who did tests, the trees planted back with the same soil grew 25% larger and had a much more extensive root system after 5 years.

When choosing a tree don’t go for the largest one. A smaller tree will settle in quicker and surpass a tree that is much larger with in five years. Remember you are in it for the long haul when you plant a tree. Like the rabbit beating the hare, the smaller tree will beat the larger tree over time.

Staking a tree is not recommended. The trunk will not strengthen properly if it is kept too stiff. The only reason you might stake a tree is to keep the roots from moving around while the tree settles. If you stake be sure to use 2 or 3 stakes and place them a foot or more out from the end of the roots.

Keep grass as far from your tree as possible.  Remember the tree roots spread out as far as do the branches.  Grass will greatly slow down and stop proper root development. The reason for this is a lack of air getting into the soil under the grass. Roots need air too.   The less grass near your tree, the stronger and better developed will be the root system. If you must have grass near your tree make sure you find a way to get air to the tree roots under the grass. ( ref. Agricultural Testament)

Written by Linda MacPhee-Cobb

March 27th, 2008 at 5:00 am

Posted in how to

Tagged with , , ,