Preventing Salt Accrual In Your Growing Medium

The majority of your plants may be growing great while one or two are struggling to keep up with its crop-mates. At harvest time you might notice that the root ball is small and dense with a discoloration at the tips of the roots. This is normally due to an unhealthy accrual of salts. The salt comes as a by-product of a nutrient solution that has been mixed too potent. You might think that a potent nutrient solution is a good thing, but the plant can only deal with so much nutrient.

The unused nutrients bond covalently with each other and become salts that, in a worst case scenario, will stunt or even kill your plants. The severity of symptoms generally depends on your growing method. A hydroponic method such as Ebb & Flood is usually pretty safe when it comes to salt accrual, but if you’re adding too much nutrient mix to a solution that is not pH balanced you’ll run into troubles. A salt accrual problem will begin to show up in your crop at about week four when using the Ebb & Flood method.

Another popular hydroponic method is Peat & Perlite. This method is known to accrue salts early in the growing cycle, usually in the second or third week. The growing medium holds on to salts tenaciously. The solution is to pH balance your nutrient solution and follow the directions on the container for mix ratios. This will prevent your nutrient solution from bonding with the other chemicals, producing salts. The easiest way to get rid of salts is to feed them pH balanced water once a week. That is, pure pH balanced water with no nutrient. You want the water to have a neutral pH of 7.0.

In the case of peat and perlite, the pH balanced water will leach the salts closer to the bottom of the growing container and out of the reach of the roots. In the Ebb & Flood method, you’ll want to flood your growing tray with pH neutral water twice. This makes sure that any leftover salts are leeched away. Spot a salt buildup problem by seeing the lowest leaves on your plants go brown at the tips and curl under. The first solution to pursue is a nitrogen deficiency.

Add more nitrogen for a week to see if it is doing any good. If leaves that are higher up on the stalk are showing the same symptoms of the lower leaves, you have a problem with salt accrual. Reduce the potency of your nutrient solution. Rinsing with pure pH neutral water will stop salt accrual is just about every growing method. Do give it a try.