HortiCOOLture - Flowers Turning Into Fruit

Developing pear fruit.

I was in my garden the other day and saw these tiny fruits.  They look dainty now but soon they can be up to one-pound-size fruits.

The fruit of the pear (Pyrus communis) is considered an accessory fruit.   Accessory fruits are sometimes referred to as false fruits because technically, the fleshy part of the fruit that we eat is not the fruit.  Instead it is the enlarged receptacle.  The fruit is described as the ripened ovary.  In the case of the pear or apple the actual fruit is the core.  If you look at the picture above, remnants of the flower other parts are still visible and yet the receptacle is obviously in the process of enlarging.   The receptacle will continue to enlarge and envelop the developing fruit (core) which contains the seed.  Thanks to the receptacle or else the pear fruit would be of little food value.  To understand this concept better, look at the illustrated parts of a flower.

Stroll in your garden...it's good for you and your plants.

Germination

Before I talk about germination I would like to start by comparing two types of seed based on their water content at maturity:

1.  Orthodox seeds are those that can withstand drying and freezing after maturity.  For example corn (Zea mays) and beans (Phaseolus vulgaris) are traditionally dried after harvesting and sometimes they may be kept in low-temperature environment for storage.  This process helps maintain the viability of the seeds for a longer period of time.  Most annual plants have orthodox seeds.  As the seed matures, its moisture content decreases while dry matter content increases.

2.  Recalcitrant seeds (as in avocado) lose their viability when their moisture content is reduced to a certain level.  Unlike the orthodox seeds, drying and freezing recalcitrant seeds damage the embryo.  Examples of plants with recalcitrant seeds are mango, cacao, and avocado.  As the fruit matures, the seed moisture content increases.  At this point the seed is capable of germination.  Recalcitrant seeds should not be dried after they are extracted from the fruit.   

Germination is the sequence of events in a viable seed starting with the imbibition of water that leads to the growth of the embryo and the development of a seedling.

Cecile Brunner

Rosa polyantha 'Cecile Brunner' 

This is the time of the year when my Cecile Brunner rose is at its best. It blooms with a showy display of dainty pink flowers in the spring. My Cecile Brunner rose is strategically located next to the front door the house where it climbs on one of the entry-way columns. The flowers are mildly fragrant but with so many of them they make a sweet statement giving a pleasant welcome to anyone who approaches the house. Cecile Brunner is supposed to bloom repeatedly till fall but the high temperatures in El Dorado Hills (our area) seem to reduce and sometimes inhibit flowering in the summer.

Cecile Brunner is a polyantha rose. (Polyantha implies a small vigorous plant that will cover itself with trusses of tiny blossoms.) According to literature, this rose was introduced in 1881. Tiny 'Tea Rose' shaped blooms, under 2 inches in diameter, are coral pink.  It has thorns on its stems which couild be very sharp.  Based on my experience, it will flourish even in marginal soil or partial sunny conditions.   My Cecile Brunner is obviously a climber but traditionally, it is a compact shrub.
The climbing Cecile Brunner is not for small spaces. If you must have them, then make sure to prune it regularly.  This is a vigorous grower.  Years ago, I planted two of them in one corner of my yard. Eventually, it got so heavy that the arbor that my husband built to support it collapsed. In addition to that, it also covered and choked my Fuji apple which was growing next to it. We had to dig them out and allowed the apple tree to flourish.

Stroll in your garden...and tend your plants. Train them to grow the way you want them to.  :)

Avocado Seed

Germinating Avocado (Persea americana) Seed

A fact about the avocado seed.

The avocado seed is a recalcitrant or homeohydrous seed.  Recalcitrant seeds are those that cannot withstand desiccation or drying and freezing.  An avocado seed would loose its viability when dried.  (Viability is the ability of a seed to germinate.) When you are planning to grow an avocado from a seed, it is recommended that the seed be kept moist until the new plant emerges. 

How to germinate an avocado seed?

This is the only method I use to germinate avocado seeds.  It works all the time and it is very easy.  This is better than directly planting the seed in the ground especially in dry places where sufficient soil moisture is hard to maintain.  

1.  Take the seed from a ripe avocado fruit. 

2.  Immediately wrap the seed with wet paper towel.

3.  Place it inside a sandwich bag and seal.

4.  Place the sealed plastic bag with the seed in a warm place (near the window or fridge).

5.  Wait for several weeks until the seeds cracks.  Do not allow the paper towel to get dry.

6.  Continue waiting until the radical (the first root) comes out.

7.  At this point you can plant the seed in a pot or directly into the ground.  

8.  Keep it watered.

This procedure is far more effective and a lot easier than the "toothpick" method.

HortiCOOLture - Interesting Tree Bark

Layers of peeling bark on a birch tree

This is an interesting bark display on a birch tree which I see often as I walk to Starbucks on most mornings.   For this tree, the peeling bark coupled with its soft earth-tone coloration is definitely its most distinctive feature.   I wonder what variety of birch tree this is.

HortiCOOLture - Japanese Maple

Acer plamatum 'Bloodgood'

Starting today I plan to post a 'HortiCOOLture' picture every Sunday.  This would be something that speaks of the wonders of plant life and their environment.  To begin with, I have this  Japanese Maple leaves and samaras taken after the rain. 

Samaras are a type of fruit where in the seed is enclosed by a thin tissue that extends out forming a wing-like structure. The wing-like structure eventually facilitates the natural transport or dispersal of the seeds. 

 
That is very cool!

Peach Leaf Curl

Distorted peach leaf

The Disease.  Leaf curl is a fungal disease that affects peaches.  It is caused by a pathogen called Taphrina deformans.  I guess that the word 'deformans' reflects the nature of damage on the plant instead of the fungus itself. Infected areas of the leaves appear thickened and reddish in color.  They turn into distorted or malformed leaves.

In My Garden.  Every year, this disease shows up on my one and only peach tree.  Right after the first set of leaves appear, infection follows.  When the leaves are all deformed and discolored, the tree seems hopeless and not fit for any serious photosynthesis.  Fortunately, the disease can only survive under cooler and spread with the aid of the rain.   As the temperatures rise, the infected leaves fall off.  In some previous years I also helped the tree by had-picking the infected leaves.  This reduces the chance of the disease spreading on new leaves and thus shortening the overall "leaf curl period".

Currently, the temperature here is about 58º F and raining.  The weather still favors the development of the disease.  However, I noticed that most of the infected leaves have fallen off the tree and the proportion of healthy leaves is now more than the red-distorted ones.

In Your Garden.   If you have this problem on your peach tree, don't despair.  Read and understand the life cycle of Peach Leaf Curl.   Acquaint yourself with your climatic condition in relation to the requirements of the pathogen.  Although the disease can affect the yield and growth of your tree, the potential extent of damage is controlled by nature itself with some preventive measures from you.

Stroll in your garden...get acquainted with your unseen enemies.  For it is much easier to subdue them when you know their secret life.