The best grapes to grow in Phoenix area are Vitis vinifera, European varieties. Flame seedless grapes and Thompson seedless grapes are the most common and are readily available for purchase at local nurseries. Black Moukka and Valencia also grow well in our climate. The lower desert summer heat encourages these varieties to produce lots of sugar, producing a deliciously sweet flavor. Since the summer heat can prevent grapes from attaining full pigmentation, the only way to know when they are ready is to taste them!
Grapevines need the support of a fence, a trellis, or an arbor. Prior to planting, prepare the supports so that the new grapevines can be trained to them. Wrap canes around the arms of the trellis, or use soft ties to attach canes to the trellis. Eventually, the grapevine’s tendrils will grow and grab onto the support, and ties will no longer be necessary. To maximize yield, prune grapes annually when they are dormant. Photos and grape vine pruning instructions can be found here. The varieties mentioned previously should be cane pruned.
To plant grapes, dig a hole that is at three times the height and width of the rootball. Mix the native soil that you removed from the hole with compost, and back fill the hole with enough of the soil/compost mixture so that when you place the rootball in the hole, it sits slightly lower than ground level. Backfill the hole with soil just to the top of the rootball, leaving several inches recessed to create a watering basin. Do not pile soil up against the stem or bury any portion of the stem. Water to settle the soil and to give your vine a good start.
After planting, spread a few inches of wood chip mulch on top of the soil to help conserve moisture and to supply some nutrients. There is no need, and it may be counterproductive, to fertilize the newly planted grapevine.
Whether you use flood, sprinkler or basin irrigation methods, grapes should be watered regularly, on an even schedule. As with trees, infrequent, deep watering is best. In the summertime, grapes may require water more than once per week. Be sure to water to a depth of at least 2 feet, preferably 3 feet, and allow the top few inches of soil to dry out before watering again. A regular watering schedule will help to produce larger grapes, although grapes grown in Phoenix tend to be smaller than grapes grown commercially in other climates.
During the wintertime, when grapes are dormant, cut back the water to once per month.
Once your vine is growing vigorously, regular applications of a balanced fertilizer during the growing season will help it to achieve maximum production. Phosphorus is beneficial to produce flowers and fruits.
Grape Leaf Skeletonizers, a type of caterpillar, are a common problem in the low desert. If you have one or two grapevines, you may wish to control them by picking them off manually or brushing off the eggs. Use gloves, as the hairs on the caterpillars can be irritating to the skin. If you notice leaves that have been eaten, leaving the ribs behind, look for rows of eggs and tiny caterillars underneath the remaining leaves. You may also spot the adult form of this caterpillar, which is a small, iridescent blue or purple colored moth.
If manual removal is not effective, one of the best organic options is a treatment of BT, which stands for Bacillus Thuringiensis, a bacteria that is fatal to caterpillars. BT does not affect other critters in the garden, including other insects, and it is not hazardous to people. The only downside to BT is that it is relatively expensive and degrades quickly in the sun, so that frequent applications may be necessary. Additionally, since it is a live bacteria, it cannot be stored for long periods and should be kept in cool, dry conditions.
When grapes ripen, birds will be attracted to them. You can cover the vines with bird netting, but it can get tangled easily and is a pain to work with. I prefer to cover my grapes with tulle netting (wedding veil material.) You could also cover individual clusters with mesh bags or nylon material that stretch and allow light through.
Homemade Basil Grape Jelly
If you love grape jelly, or if you could 'take it or leave it,' give this recipe a try. Not your average ho-hum partner to peanut butter, this jelly has a depth of flavor provided by a few key secret ingredients, revealed here. Tart and sweet, your favorite purple grape juice provides a base for the recipe...along with your own organically grown grapes. Choose a high-quality juice. The higher the juice quality, the better the jelly flavor! I prefer an organic juice with no added sugar, but any grape juice will do!
Simple, delicious, and fool-proof, this jelly is wonderful for a lazy weekend morning, and it makes a unique gift that's fun both to make and to give!
Photo credit: The Micro Farm Project
This recipe makes about 4 half-pint jars, or twice as many 4-oz jelly jars. You could also pour this jelly into pretty, clear glasses, sealed with household wax.
Whatever containers you decide to use, be sure to sterilize them in advance in boiling water or in the dishwasher on anti-bacterial setting. Sterilize the jars, as well as the lids and rings. If you boil them on the stove, leave the empty jars in the hot water until you are ready to fill them so that the jars will remain hot. If you sterilize them in the dishwasher, use the "heated dry" setting so that the jars will stay hot. While the jars are being sterilized, prepare your jelly.
1/2 C. boiling water
1 tbs dried basil (or Thai basil)
1/2 tsp ground cardamom
pinch of salt
3 1/2 C. pure cane sugar (I prefer raw sugar)
3 1/2 C. purple grape juice
2 C. seedless grapes (skins removed, see below.)
3 oz liquid fruit pectin
Optional: paraffin wax
The flavor of basil and cardamom is delicious, but they cannot be added directly to grape jelly or the gritty, chewy pieces ruin the smooth texture. Basil and cardamom flavor can be added to your recipe indirectly by steeping them to draw out and capture their essence in a liquid form, while the solid stems, leaves and pieces can be discarded.
Pour boiling water over basil and cardamom in a saucepan and set aside for 10-15 minutes. Strain the herb brew into a 4-quart saucepan through a fine strainer or a colander lined with cheesecloth or a paper towel. Discard the herbs. Reserve the fragrant liquid in the saucepan for use in your recipe.
Freeze 2 cups of seedless grapes. To remove the skins, place frozen grapes in a colander and run warm water over them. The skins should slide off easily. Puree the skinless grapes in a food processor or mash with a potato masher.
Add mashed grapes, grape juice and sugar to the herb water in the sauce pan. Stir over medium heat until the sugar is completely dissolved. Then increase the heat and bring the mixture to a rolling boil.
Stir in the liquid pectin and return the mixture to boiling. Boil rapidly for 1 minute, stirring constantly.
Remove from heat and skim off the foam that will collect on top.
Note that foam can be reduced by adding 1/2 TBSP of butter to the saucepan prior to pouring in the pectin. Butter is completely optional, and does not change the flavor or texture of the jelly
Pour the jelly into hot, sterilized containers. Use a wide-mouth funnel to prevent sticky drips from running down the exterior of the jars. Seal with lids or paraffin.
To seal with paraffin wax, allow the jelly to cool for several hours. Then melt the wax slowly over low heat. Paraffin is flammable, so keep your eyes on it at all times. When the wax is completely melted, pour 1/4 inch of the liquid wax directly on top of the jelly in each container.
Note: If jelly does not set, pour it back into the sauce pan and bring to a rolling boil for 1 minute before returning it to the jars.
Store jelly in the refrigerator and use within 3 months.