How to Tell if Your Fruit Blossoms Froze

 

You can see the yellow style that extends up from the pistol in the center of these plum flowers.

Every time the temperatures dip down to freezing, you worry about loosing some or all of your fruit crop. Apricots, plums, and peaches cause the most concern because they have such early bloom times.  In New Harmony, plums can be in full bloom, apricots dropping petals, and peaches just starting to bloom at the beginning of April.  With an Average Last Frost Date in mid May, each cold front threatens the crop. So what are the critical temperatures?  Let's look at some facts.

Dormant fruit trees can tolerate very cold winter temperatures. As we move into the warmer weather in March, April and May trees and small fruits lose their winter hardiness as the tree breaks dormancy. As buds begin to swell, the ability to tolerate cold temperature changes with each growth stage. 

This range of damage from cold varies with the growth stage of the buds, fruit species, age of the tree, and even the cultivar. 

On this photo you can see the blackened pistil of an apricot flower.

 Early in development, at first green and green tip stages, temperatures need to drop into the teens or lower to cause significant bud damage. 

Temperatures in the upper 20s can cause considerable harm to an early blooming species or variety and leave other fruit crops unaffected or with only slight damage. 

The stage of bud development determines how susceptible any given fruit crop is when freezes occur.

At or near the bloom stage, the critical temperature is the same for almost all fruits and flowers. Freezing temperatures of 28 degrees Fahrenheit will result in about a 10 percent loss and 24 F in a 90 percent loss. In a freeze with clear, calm conditions, fruit on higher sites or in the tops of trees will be less damaged than those at lower sites. 

Heathly peach blossoms

Stone Fruits:  Apricots, Peaches, & Cherries

After a freeze, people often want to know if their fruit took a hit. It takes several hours for the symptoms to develop. As frozen tissues thaw, they will turn brown or black if they were damaged or killed by the cold.

The buds of stone fruit trees are either flowers or leaf buds, and not a mixture of both. In cherries and plums where there is more than one flower, all the flowers in a bud are about the same age.

Stone fruits have a very simple flower structure and are the easiest to detect damage. The flower contains a single pistil (the female part of the flower that will become the fruit)  If the pistil is brown or black after a freeze, that flower will not develop into a fruit because the pistil has been killed. Early in the season, when the buds have swollen but not opened, the flower buds can be cut open across the bud to inspect the pistil. If this is black, the flower has been killed and the fruit will not form. A healthy green pistil means the bud is alive. 

Peach flowers are harder to assess because of the fuzz on the pistil. Having a heavy bloom is helpful because only a small number of flowers are needed to get a crop.  If you have a heavy bloom and lose flowers, the crop may not be severely affected.

Crop losses due to freezing temperatures are almost always significant in cherries.

After flowering, small stone fruits are in the shuck. The shuck is formed by the floral cup. The shuck provides a little protection from the cold when the fruit is small and not touching the sides of the cup. When the fruit fills the shuck, the shuck provides no protection at all.

Apple blossoms notice the large king bud in the center.

Apples and pears

Apples and pears are very different than stone fruit.  In apples, the fruit buds are really small shoots with both flowers and leaves.  In apples, the flower in the center of the flower cluster is the oldest and most developed and will be the first flower to bloom. This central flower is called the king bloom and is the most desirable of the flowers in the cluster. The king bloom has the potential to be the largest fruit.

Since the king bloom is also the most advanced flower in the cluster, it is most likely to be killed in a frost. Another difference between apples and stone fruit is that the pistil is buried inside the base of the flower and not exposed above it as in stone fruit. This means that it is often necessary to tear the flower apart to see if the center of the flower is brown or black. 

So basically if a fruit tree is blooming that is when it is most susceptible to damage.  But always take a closer look at the flowers and actually examine them for damage. This information comes from various Extension Offices.

Growing Strawberries

Fresh strawberry pie, strawberry rhubarb pie, fresh strawberries, and strawberry freezer jam, just think of the possibilities if you had your own strawberry patch.  Strawberries have to be one of the most popular berries grown in the home garden, yet I find that people know little about proper cultural practices concerning strawberries  Most people mistakenly think home grown strawberries are small and yields are scant.  Perhaps we need a refresher course on proper management of an existing bed and how to plant a new strawberry bed.

Strawberry Pie Filling and Topping

Strawberry Rhubarb Jam 

Dehydrating Strawberries 

Stawberry Watermelon Lemonade

The bed on the left are Tristar and Ozark Beauties are on the right.

 

• Strawberries produce best the first through fifth years
• Strawberries need well drained soil with lots of organic matter
• I prefer growing them in a 4x8 foot raised bed but they can be grown in rows.  Rows are more difficult to manage.
• It's best to buy bare root plants in early spring.  They are usually sold in bundles of 25
• Plant in multiple rows offset in a raised bed.  Try to space plants 6-8 inches apart. 

 Planting and Early Care of Strawberries

• Work 2-4 inches of organic matter into the soil.  Be generous and your harvests will be better.
• Also incorporate a dry organic fertilizer into the bed.
• During the first year, remove the runners with scissors
• This will encourage root growth and development
• Fertilize with fish emulsion the rest of the season
• Strawberries have shallow roots and require up to 2" of water when fruiting
•  Infrequent and too little watering are the biggest reason for small fruit and small yields.  Not thinning will also result in small berries.
• Strawberries are drought tolerant in a landscape setting but will not be productive when it comes to fruiting if drought stressed
• Mulch around the plants
• Keep weeds out

 

Harvest with caps and stems.  Hopefully you have some left to take inside.

Managing the Strawberry Patch

• In winter, let the plants die back and leave them alone until spring
• In spring when they start to green up, remove all dead debris
• Thin plants back to 6-8 inches apart 
• Thin each plant to 5-10 crowns per plant
• Sprinkle a dry organic fertilizer around the plants and side dress with a chelated iron and water thoroughly
• Add mulch around plants

 Types of Strawberries

June Bearing

• Need short fall days to initiate flower buds
• All flowers that are going to bloom next summer are set in the fall
• Produce one abundant crop in early summer
• Good large berries with a concentrated harvest over short time period
• They are classified into early, mid-season and late varieties.
• Varieties include Guardian, Earliglow, & Allstar
• Good for commercial growers or if you want a concentrated harvest for processing.

Real strawberries are red all the way through.

 Ever Bearing Strawberries
   

• Initiate flowers in fall that produce the following summer
• Also initiate flowers during summer
• Produce second crop in summer until frost
• A good variety is Albion which is my all time favorite.
• Ever bearing are my favorite type of berry.  You basically  get berries from early summer until the first frost.  The spring berries are smaller than the later berries.

Dehydrated strawberries are on of my favorite snacks.  

Day Neutral Varieties

 

Do not require short day to initiate flowering

They start producing once they reach a certain maturity level

They produce a larger crop in the early summer and late fall

They produce sporadic crop throughout summer

Good varieties include Tri-star & Tribute

Harvesting Strawberries

 

•Morning is the best time to pick.  Berries are firmer

•Pick with stems and caps on

•Refrigerate as soon as possible

•Do not wash or remove caps until ready to use them

•Carry a ziploc bag when you are harvesting. When you encounter a berries that have rot or mold put in bag and throw away. 

•This will minimize spread of fungal disease

 

Freezing berries is easy. Individually quick freeze them on a tray lined with freezer paper then place in individual bags for use later in desserts, smoothies, of jams.