Hi. I am on my second attempt at growing auto flowers. Up until recently, things have been going very well. I am growing 5 Super Lemon Haze auto flowers and I am just about three weeks into the process. Two of my plants are doing very well and look very healthy, but I have three plants that are not looking so great. My process has been the same for all five plants. I am using Fox Farm Ocean soil, I have Fox Farm nutrients that I will start using in week 4, I am using an 18/6 light cycle using 300w of full-spectrum per plant, I have proper air circulation, the room temp is consistently between 70-75 with night temps around 66-68, and the air humidity is 55%. One of the plants has been in a runt stage since week 1 and has grown very little in comparison to the other plants. One plant is looking okay on top but the lower leaves are drooping and spotted. The other plant is also starting to show spots combined with areas of the leaf that look eaten away.
As a beginner on almost every level, I would appreciate any advice that can be given.
I asked because it looks like nute burn or pH problems and thought it might be Miracle Grow. Fox Farm Ocean Forest is pretty hot too and is sometimes too much for seedlings. You might have gotten a particularly hot batch of OF. Do you know your runoff PPM and pH? I know they are a little young to be measuring pH and PPM, but if you are having problems they are worth looking at. It seems unlikely, but still a possibility.
I do not know the current PPM or pH. I have not taken any measurements yet. I went with fox farm soil after high recommendation. I do not believe that I am overwatering. I have been going with the finger in the soil check. This soil seems to retain its moisture longer than expected. This soil claimed to be well aeriated with good drain. I was surprised that the plants in questions were looking rough given how health and vibrant the other plants are looking.
Autos can be more sensitive to high nute levels than photoperiod plants are. I suggest going with a less hot soil such as FF Happy Frog instead of Ocean Forest.
Maybe others will come along here with other suggestions too.
You showed us the not so great, how about the others? If all things are equal it’s hard to say what could be the problem. They look wet. Do you let them dry between watering?
Thanks for the recommendations. I appreciate it. Any advice helps. One other question for you; how tall should my plants be at three weeks? Some years ago I did a Northern Lights auto grow. First grow ever, and I used miracle grow soil, lol. Those plants were short and very bushy by week two. These plants are taller, 6", but not very bushy.
I let the soil dry appropriately between waterings. This soil was highly recommended with a claim of good aeration and drain, but it holds its moisture longer than expected. Picture included of one of my healthy plants.
When the plant is still a seedling I use an eyedropper to put a few tablespoons of water at the base of the plant. After the first couple of weeks I move to a jigger of water every few days. When the plant is established I do the flood/drought method. I water every other day or so with a good soak every week or so. Watering to runoff is a good way of preventing a buildup of contaminants. Letting the plant “dry out” between watering will build better roots.
Like I said, if all things are equal it’s kind of hard to tell you to do something. Hemp will handle a wide range of conditions and some may fair better than others. Even from the same strain/grow/batch.
Whenever I see the words “full spectrum” I wonder if it’s a blurple.
What is the light you are using? Brand and model# please.
You’re OK with that light for now. You could take the plant all the way through flower with it, but you won’t get satisfactory results without a better light.
Bring it down as close to the plants as you can to minimize stretching.
