Grapevines thrive well in almost all types or soil and all weather conditions. Once the vines grow rightly, they have a potential of producing great yield for up to 4 decades. Grape fruits and flowers grow on fresh cane buds that emerge the previous year and were dormant during the winter season. This is why it’s significant to know exactly when and how to fertilize grapevines in order to get a healthy produce. Here’s how to get it all done.
When to Fertilize Grapevines
The fact that grapes are deep rooted makes the plant need little additional fertilizers. Unless they are growing in very poor soil, the amount of fertilizers remains limited.
First year plantings of grape vines do not require fertilizer. What happens during the first season of the plant is that the vines expend energy on the development of roots. And that’s why, the first year of growth calls for just a little bit of nitrogen, low potash and high phosphorus. The idea is to encourage root system growth in the initial year of the plant, specially to make it through the cold months, thereby limiting nitrogen as it leads to excess leaf growth. So, you need to go for phosphorus to promote root development, preferably, by adding bone meal. New grapevines need no more than a teaspoon of bone meal added into the planting hole.
The second year is the time where fertilizers play a major role for grapevines. This is the time when the plant needs a light layer of compost or a 5-5-5 organic fertilizer added once in the early spring when the grapevines break dormancy.
No matter what’s kind of soil, the second year of growth calls for light fertilizers. Make sure you don’t apply more than one-fourth pound of fertilizer in circles around the grapevines at a distance of 4 feet from the vines.
Spring is the time when the buds begin to grow, and that’s when you apply plant food to the vines. Fertilizing too late in the spring may lead to unwanted growth, thereby putting the plants at risk of winter injury.
Once the vines hit the third year, a fine layer of compost added in the early spring works just perfect for the plant to yield delicious grapes.
How to Fertilize Grapevines
To witness rapid growth like every other little plant, grapevines need nitrogen, especially in the spring season. Grapevines work in great coordination with the naturally occurring fungi mycorrhizae. The fungi thrives in the grape roots, helping the breakdown of nutrients and their absorption from organic material. That’s why organic mulch and compost is so effective in bringing the right nutrition to grapevines. Make sure you avoid garden chemicals when fertilizing grapevines as it alters the balance of mycorrhizae.
The right soil pH is between 5.0 and 6.0, and that’s why it’s essential to perform soil testing before adding any fertilizers. Grapes grow great in soil that falls outside the perfect pH. It’s good to maintain some weed growth about 2 feet away from the grapevines on each side, managing the weed growth with pulling and hoeing while adding organic mulch.
Stick to January or February if going for manure to feed the grapevines. Add around 5-10 pounds of rabbit or poultry manure, or go for pounds of cow or steer manure for each vine.
Urea, ammonium nitrate, and ammonium sulfate are some nitrogen-rich fertilizers that work wonders for grapevines. These should be added when the grapes are about one-fourth of an inch across, or when the vines have blossomed. Speaking of the quantity, go for half a pound ammonium sulfate, three-eighth pound ammonium nitrate or one-fourth pound of urea for each vine.
Another mineral that benefits grapevines is zinc. It assists numerous plant functions and a zinc deficit plants can undergo stunted leaves and shoots, ending up in a reduced yield. Add zinc in the spring season a week before the blooming of the vines or when the vines are in full bloom. Spray a concentrated solution of 0.1 pounds per gallon on the foliage. The second method is to brush a zinc solution on fresh pruning cuts in the early winter.
If you witness decreased shoot growth, yellowing of the plant or summer burns, it’s a sign of potassium deficiency. The need is to apply some potassium fertilizer during the early summer or spring when the production of grapes just begins on the vines. For each vine, use 3 pounds of potassium sulfate for mild deficiencies, while going for 5-6 pounds if you find the damage is severe.