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How often to add Blood or Bone Meal?


New Member
Hello fellow growers. This is my first grow and first thread post :high-five:

Soil: 50% - Miracle Grow Premium Potting Soil, 20%- Sphagnum Peat Moss, 30% - Perlite
Container: 1gal
Light: 18/6(veg), 8 - 23watt(1600 lumen, 5K) CFL
Humidity: 55%(average)
Temp: 76f average (68 low, 81 high)
Strain: Random Seed Bag(2 sativa, 3 indica - or so it seems as of now)

It was slow going due to first time grower mistakes I made. I've finally got my grow area to acceptable(optimal?) conditions and have started fertilizing my seedlings. I'm using Blood Meal(12-0-0, veg), Bone Meal(6-9-0, flower) and Kelp Meal(1-0-2, throughout?) I started @ 1/3 strength fert of Kelp Meal and Blood Meal as of now and have only admistered the fert once.

So my question is this, how often should I add the Kelp & Blood Meal? I'm uncertain of how long these 'slow' release fertilizers will take to disintergrate and no longer benefit my plants. Is this a once and done type of fertilizing that can wait until next repot? Also, does anyone know if it is possible to fertilize with Blood/Bone Meal through watering like other nutrient solutions? I know they will dissolve in water but I am uncertain if plants will still receive the same benefits when administering as a liquid nutrient.

I've already been astonished at the speed that my plants use nutrients and grow on several occasions. Thanks in advance for any help and may you all have healthy greens & bountiful yields!

Fuzzy Duck

Well-Known Member
Re: How often to add Blood or Bone Meal??

Bone meal should last the entire grow has a slow release of around 6 months - does not disolve in water tho !

Blood meal is quick release, well its only dryed blood at best & probable break down over a few weeks to a couple of months.

Kelp meal not sure how long that last maybe a couple months or more ?

I would suggest watering with blood/kelp meal once a week, prehaps a level tea spoon of each per litre of water as a suggestion...

Might even want to include un sulfered molasse !

MG potting soil will be preloaded with chemical synthetic nutrients which will last a good few weeksif not more & will support growth/veg period.


New Member
Re: How often to add Blood or Bone Meal??

Thanks alot for all the advice! Going to start watering with Bone Meal/Kelp with next watering. The addition of this through the soil already yielded a great growth increase and am hoping to see more of this in the near future. Going to look into the sulfur molasses as you said but to be honest although I have read about the use of that on other forums/sites I don't know much about the actually application or mixture of this. Any advice or tips? I will start digging up any information I can find.


Member of the Month: Dec 2012
Re: How often to add Blood or Bone Meal??

I only add during transplanting or when im mixing new soil


New Member
Thanks Wiz. I think I am going to only add the BloodMeal into my new soil mix when when transplanting seedlings to veg. Then maybe 1 month into veg use the Blood Meal in a tea to feed. This is not applicable for my first crop since they are going to be out of veg cycle shortly but we'll see how it goes for the next round. I've done plenty of experimenting and already lost enough plants, all from bag seed thankfully, and want to make sure my Indica Lady can make it to harvest. Slow, steady, patient.

Thanks for all the advice and I wish you all healthy and abundant growth! :thanks:
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