Plant growth and stunted growth? Weekly Growth?

How much should a plant grow in say a week's time? I have a of plants that are exactly six weeks old and have grown pretty good while I have a lot more of the same plants (from seeds) that have been grown under the EXACT same conditions, literally NEXT TO EACH OTHER and are a fraction (and I mean a fraction) of the other one. I am not sure what the problem could be since they were all grown exactly the same way under the same lights, etc. etc. In any event, I think I need to pay much more attention to how much the plants are growing, they are exactly the same age but the one is soooo much bigger than the other ones. So, hence the question, how much growth should I be looking for on a weekly basis?

Any given strain has particular phenotypes. Some have just one while other types have many. You can grow multiple plants of the same strain under the same circumstances and end up with very different outcomes. For example, Mother's Finest exhibits three vastly different phenos that all come from the same parents. One pheno finishes flowering at about 2.5' while the haze pheno will grow over six feet tall in the same time frame when started at the same height.

Mother's Finest said:

Any given strain has particular phenotypes. Some have just one while other types have many. You can grow multiple plants of the same strain under the same circumstances and end up with very different outcomes. For example, Mother's Finest exhibits three vastly different phenos that all come from the same parents. One pheno finishes flowering at about 2.5' while the haze pheno will grow over six feet tall in the same time frame when started at the same height.

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Okay, got that. But now if a plant is very slow growing, and I mean VERY VERY slow growing, there is probably something wrong, correct, especially if you are growing several different strains under the same conditions?

Growth rate comes second to "perkiness." Healthy plants will have nice green leaves that reach slightly upward, the opposite of the drooping effect. Plants that have this perkiness are usually quite healthy, even if they grow slowly. Even more than different phenotypes, different strains can have huge differences in growth rate. Also, male plants will often grow faster than females, which can make an even bigger diference. Some plants even grow slowly only in veg, shooting up when you switch to 12/12. As long as the plants have that healthy, perky look, they'll be fine.


Note: Plants can reach upward excessively when the soil dries out and they are reaching for moisture. In this and a few similar rare cases, the perkiness is a prelude to wilting.

it could be a high humidity, anything over 75% closes stomata, and C02 intake slows, also slowing plant growth.
humidity and temps please?

Btownbud said:

it could be a high humidity, anything over 75% closes stomata, and C02 intake slows, also slowing plant growth.
humidity and temps please?

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The temp is 79-80 and the humidity is about 20-25 percent. I am using a 600 HPS and 4 out of 8 T5 full lumen bulbs. I would use the other 4 but the temperature shoots above 85 degrees and my air-conditioner can't seem to handle the added lighting.

Last night, I did just transplant several of my plants including the one that has grown fairly decently. It is about a foot and did in fact seem to be root-bound (as the roots were traveling up and down the sides of the bucket) even though it was in a 3 gallon bucket at that time. I watered the plant at the same time last night as transplanting and am planning on waiting about 6 days before watering it again to ensure that I am not over-watering.

However, the rest of the plants seem very small and seem to have hit a plateau but hopefully things will change soon.