Fruit Tree Pruning

It’s not too late to get your dormant pruning done
As fruit trees mature, they must undergo two pruning phases. When the tree is young, the first phase consists of cuts to select the primary scaffold and heading and thinning cuts to create the secondary scaffold. In trees over 5 years old, the second phase begins, in which fruiting wood is maintained and renewed by thinning and heading fruiting and non-fruiting wood. Thinning cuts refer to the complete removal of branches and are applied to promote space for aeration, light penetration and fruit maturation. Heading cuts refer to the removal of portions of branches and are applied to force and direct branching and spur development and to restrict overall size of the tree.
In both phases, general pruning principles apply. First, remove all dead, dying and diseased wood. Second, remove all branches and limbs that grow toward the center of the tree. This promotes aeration and light penetration to the fruiting wood. Third, thin branches and limbs that cross or touch so that abrasions do not develop. Finally, remove any suckers growing off the rootstock above or below the ground.
You will find that heavy pruning encourages the formation of water sprouts and vegetative growth at the expense of fruiting woods. Light pruning, on the other hand, encourages heavy fruit set which results in smaller fruit of poorer quality and possible broken branches. Since home growers must also keep trees to manageable sizes, strive for a balance between heavy pruning and renewing fruiting wood.
In order to achieve this, you should know where your tree bears its fruit.
ALMONDS produce on spurs that remain productive for up to 5 years. Remove water sprouts and head and thin as necessary. As the tree matures, remove older, unproductive spurs to generate new spur growth.
APPLES produce fruiting spurs on wood 2 years and older that are productive for 6 to 10 years. Thin out branches to admit sufficient light to all parts of the tree; this will encourage new spurs to develop. Remove older, unproductive spurs as the tree matures. You may also need to thin spurs. Up to two-thirds new growth can be cut back annually.
APRICOTS bear the bulk of their fruit on 2 year old wood. All new growth can be cut back approximately by two-thirds. This wood will grow fruit spurs the second year and produce fruit the third year.
CHERRIES are borne on long-lived spurs that are productive for 10 to 12 years. When trees are young, head back main limbs one-third to create branching. Continue heading to create more branching and thus, more spurs. Because spurs are long-lived, thinning cuts tend to predominate pruning in phase two.
FIGS produce fruit on 1 year old wood and the upcoming season’s growth. They require little specialized pruning; head back to keep tree to manageable size and thin to keep aerated.
PEACHES AND NECTARINES produce fruit on last year’s growth. Remove about 50 percent of current season’s growth annually. On younger trees prune whips back to 12 to 24 inches. Use thinning cuts to promote aeration.
PEARS bear fruit on spurs on 3 to 10 year old wood. Main limbs are usually headed each year and side limbs are lightly headed or left unheaded, producing spurs and fruit in future years. As in apples, remove older, unproductive spurs and thin middle-aged spurs. Up to two-thirds new growth can be cut back annually.
PERSIMMONS bear on the current season’s shoots. Pruning consists of thinning shoots to promote growth for next season’s crop and heading cuts to keep fruit within reach.
JAPANESE PLUMS AND ITALIAN PLUMS (PRUNES) bear on fruit spurs which live 5 to 8 years. For varieties that bear heavy crops, remove one-half of the shoots each year. Other varieties, like Santa Rosa, bear moderate to light crops so remove only one-quarter of the shoots.
WALNUTS produce fruit on spurs on 5 year old wood that remains productive for up to 15 years. For the mature tree, a pruning program can consist of applying the general pruning principles described above.

SUMMER PRUNING assists home orchardists with the goal of keeping trees to manageable sizes. Typically, the whip emerging from dormant season heading cuts are themselves headed and thinned in August or after fruit harvest. By removing this growth, you remove leaves which would otherwise generate food for the tree and thus, vegetative growth. Since most rootstocks, even those labeled ‘semi-dwarf,’ are primarily developed for soil and climate adaptation, pest and disease resistance and early bearing, controlling the size of the tree becomes the home orchardist’s responsibility. Many trees, especially Apple, Pear, Apricot, Peach, Nectarine, Persimmon, Fig, and Plum trees, can be kept to 10 to 12 feet utilizing summer pruning. Trees this size are more easily sprayed, pruned in winter.

 

Figs – Stretching the growing season

In the past we have focused on trying to grow figs by insulating them over the winter.  Our problem has been that while the plants live and even get bigger each year, the main trunks and branching freezes back to the ground. In the summer when warm enough, it regrows and develops figs.  Our season isn’t long enough to regrow all the plant, then set and also ripen a crop.  When the first freeze hits we are left with many green, quarter-size figs on the bushes.

This year we decided to change our approach. Instead of trying just to keep branches alive through the winter, thereby fruiting earlier in the season, we are going to try extending the length of the season.  Because our bushes are in a row, this easily lends itself to covering with a “low tunnel”.  A low tunnel , as opposed to the better known and walk-in “high tunnel” or “hoop house” is a miniature hoop structure about 3’-4’ tall that is covered with plastic, usually white instead of clear. This allows diffused sunlight to warm the interior, keeps off the wind and gives a small amount of insulated protection at night, while allowing the covered soil to radiate warmth. These were originally designed to set over a row of vegetable crops to get a jump on spring growth and also in fall to have a longer season.  Usually they have to be monitored during the day and opened if it gets too hot inside.  Since figs love the heat and will mature quicker, we are planning to keep it totally closed.

All hoops in place

 

Checking the weather Friday showed that we were due for our first freeze Saturday night. We needed to work quick to have a chance saving this year’s crop!  Luckily we had the materials we needed already on hand and Saturday morning we got to it.  Our first step was to pound 2’ lengths of rebar into the ground every 3’ or so, in two rows.  One row on each side of the bushes.  The next step was to take 8’ lengths of PVC pipe, bend and place over the rebar, one side to the other.  These are our ”hoops” or “ribs” and are an arch of approximately equal width and height.

Tying the hoops together

Next we took some poly twine and with Russell’s Boy Scout knot tying skills we tied each hoop to the next using a single piece of the twine.  This stops any independent movement of the hoops and makes the whole structure much more rigid.  That was the easy part and took two people about 1 hour to complete for an approximate 30’ length.

 

The next step is where we varied from normal hoop structure.  We had some Agribon-19 floating row cover that was on a huge roll I got for the vegetable garden.   Row cover is made from white premium grade spun-bond polyester and has “pores” large enough to let in 85% of the sunlight, water and air, but small enough to keep out insect pests.  A single layer gives 3-4 degrees of insulation or cold protection.  We opted to put on 2 layers hoping to get even better frost protection maybe down to 26.  Our weather forecasts show that upcoming freezes for the next 3 weeks should not drop this low, but who trusts the weathermen?  After applying the row cover we clipped it at the ends only to hold it on while we did the next layer.  The clips are about 3” long aluminum and like a pipe slit down the side.  They are made to go over ¾” pvc and hold thin plastic.  What a life saver these little gadgets have been!

Lastly we were ready to cover the unit with plastic.  We used clear plastic since we want as much solar gain inside as possible and also because the row cover will diffuse any direct glare.  A ten foot wide piece was selected leaving a foot extra on each side when covered.  Then we took some 16 foot long 2” x 4” ‘s and rolled the bottom plastic on them. Once rolled, we used a staple gun to secure the plastic to the boards.   At the ends we just gathered and bunched the extra film and tied it off with some twine. To look inside all we need do is lift a side towards the middle or open an end up.

We will see if we can extend the season long enough, but probably the middle of November is all we will get.  After the plants go dormant we will bend them down, cover with straw and keep the cover on it.  Keeping wind off, combined with some daytime warming way keep the plants branches from total freeze off. Regardless we should also get a jump on the growing season in the spring and maybe an artificial  “early” spring combined with a ”late” fall would be long enough to mature the fruit even if we have to regrow the branches and stems.

 

Various Fruit Experiences

As we start our third growing season at Road’s End Farm it is time to write about some of our observations and results with the many types of fruiting plants that we grow.  As you know our mission is to develop and promote varieties that are suited to culture in the central New Mexico mountains and similar locales.  We want you to be successful by helping you choose varieties that will profitably produce for you.  Our method is simple in that we take our best educated guess from years of growing, listening to others experiences and add some of the latest varieties to the mix.  We then grow these and see which do best or in some cases do poorly.

Of course results may vary depending on the care, location, microclimate etc. that you give a certain plant.  In those cases we will make recommendations for location and culture.  Our plantings are not babied as you might do at home. They are planted in the field with no shade and treated as a commercial crop would be.  In many cases the planting stock we have purchased has been very small, maybe suitable for a 4” container or was a 4-6” bare root plant.  Such is the way of dealing with new or rare varieties, they just may not be available in a size we would prefer.  Often is the time we felt a larger plant would have survived or thrived whereas the smaller one could not adapt. We will discuss these possibilities as we go through our series of posts.

For those of you more detail oriented, the soil ph at our farm is 8.2 which is considered very alkaline.  Our water comes from fractured limestone and also has a high ph and is very “hard”.  February 2010 recorded minus 34f and summer 2011 recorded a high of 102f.   Most research on “hardiness” of plants is focused on the coldest temperature they can live with and very little research has been done on the warmest temperature they can take.  When we make selections to trial we find ourselves choosing from varieties that may do well in the upper great plains or in Russia’s colder areas. In the case of heat we will discuss it when it applies.  I hope to be able to cover at least 1 fruit type a week in an informal and unscientific manner, but this time of year is always short on “spare writing” time so don’t hold me to it.