Fertilizing Your Plants
I have a question about which fertilizer to use during seedling, vegetative and flowering growth. Please recommend brands and their corresponding nitrogen-phosphorus-potassium percentages. I don’t want to burn them with too much nitrogen at any stage of growth. BTW, I’m growing in soil.
Timmy G.
Amarillo, TX

Dear Timmy,

First, you have to start with good soil. Look for a rich organic blend such as Garden-Ville potting soil. It’s made from compost, Canadian peat moss, perlite, orange sand, cedar flakes and other ingredients. I’m not crazy about cedar flakes because they take up nitrogen to decompose, but the level is low. They also help provide drainage and aeration. Look for a good local brand of store-bought organic soil.
The water from Amarillo comes from Lake Meredith (60%) and groundwater (40%). Amarillo is in farm country, and farm chemicals and fertilizers could leave the water tainted. Request a water analysis from your local water district (to determine the pH) and a list of dissolved solids in the water. If the level of sodium is more than 50 ppm and the total dissolved solids level is more than 300 ppm, you should treat the water with reverse osmosis to remove dissolved salts. The pH should be between 6 and 7 for good nutrient uptake.

There are many good organic fertilizers to use. A partial list includes Canna, Earth Juice, Fox Farm and Formula X. Use the fertilizers as directed for seedling, vegetative and flowering growth. You should also purchase a biostimulant to increase fertilizer uptake and soil life. Biostimulants often contain humic acid, fulvic acid, trichoderma, and a host of good microbes and bacteria that promote growth. Many companies carry biostimulants.

Vegetative plants need a full range of macronutrients and micronutrients and use a lot of nitrogen, which washes out of the soil quickly and must be replaced regularly. Some strains, such as Sweet Tooth and Big Bud, are incredibly easy to grow and can take high doses of fertilizer.

Change to flowering fertilizer a few days after turning the light to a 12/12 day/night schedule. Flowering fertilizer should contain higher levels of phosphorus (P) and potassium (K) and less nitrogen (N). Adding an additional PK 13-14 supplement for the last four weeks before harvest will swell buds to a nice, tight, compact mass.