Hi, I bought two Bougainvillea plants back in April and am having different levels of success and not sure why they aren't growing at the same rate.

On the attached picture, the one on the left is thriving and doing well. The one on the right is struggling. They are both west facing and I am in zone 9b. My two theories is the one on the right has a tree that blocks some of the afternoon sun and the neighbor next door has a bit of a moist lawn which could be too much moisture for it (my moisture sensor says it isn't really that much more damp than the left plant). Do you think think that the weakness of the right plant is due to both or one of those two reasons or something else? Any suggestions to help the growth would be appreciated as well. I water them once a week with a gallon of water each and they get a little bit of moisture from the sprinklers but not a deep watering.

Thanks in advance.

I don't think 1 gallon of water a week is nearly enough. I suspect the one on the left is taking advantage of water from another water source. Bougainvillea are drought tolerant, once they are established. But until then, they need regular deep water. What kind of soil do you have? If its like the rest of Sacramento, silt and hardpan. Is there a layer of hardpan under either plant?

Have you tested to see how far your 1 gallon of water gets? Your moisture meter is only telling you what's happening in the top 6 or 8 inches - the water needs to be below the roots to draw them down. Find a stick (bamboo, dowel, ...) and push it into the ground in the middle of the rootball as far as it will go. Leave it for a minute and pull it out. You will be able to see/feel wet or dry spots in the soil. Use a dry stick and test the second one also.

Is the one on the R in a pot?

I had them planted to get full sun when I lived in the Caribbean and have them in pots in full sun year around with a southern exposure here in Texas. They are drought tolerant but only once established. Some have a smaller root system and grow slower than others. I would not worry much if you provide enough water, have no soil nutrient deficiencies, give them >6 hours of sun at all times of the year and the plant was not root bound when planted. Remember that the sun is now angled differently and it may be getting less than 6 hrs of sun. Hope your soil is not compacted!

@DaisyI: I'll do a check on the water and probably will add more. Yes, the soil underneath is claylike hardpan. I was concerned that if I watered too much the water would go through the topsoil, sit on the hardpan and potentially cause root rot. I read a lot about bougainvillea disliking too much water. I will get the right one more water and see how it goes.

@purpleinopp: Yes, they both are in the pots that they came in. I had made four vertical cuts in the pots for the roots to grow out of.

@luis_pr: Thanks, per above, my soil is claylike, so probably is more on the compacted side if that's what you mean. Our summers are definitely hot with zero moisture. I don't mind being patient but I just don't want the plant to die come winter as the temps can dip below 30F a couple of nights!

Appreciate all the help!

It looks like the one on the right side is in a container. So I assume that has a lot to do with the problems you are having.

I agree with Andrea, grounding them with the pots isn't an ideal situation.

Why did you leave them in the pots?

@DaisyI: I had read on a bougainvillea website that their root system doesn't like to be disrupted so it is better to plant them in their grow pots and make cuts on the side for roots to come out of. I don't think I'll be doing that again though.

I doubt the plant on the right has made it out of the pot. Tug on it and see how well attached to the earth it is.

This is my first time hearing this advice for any plant, but I haven't read all of the available advice out there. If you want to try planting again, cutting the pot off should be do-able without disturbing the roots at all.

I tried that cut pot thing wi th a Brugmansia only to later find very little root growth out of the pot. And sad plant.
Bet its stuck in the pot.
Seems to me you can unpot and plant without disturbing roots.

Their roots do not like to be disturbed but I have not had issues before. Then again, I am aware of the reputation and exercise care. In pots, they may get root bound though so be aware.

Thanks, you all appear to be correct. The pot came out with a little bit of a tug. See photos. I don't think the roots got out of the pot as well as they should have. I took the pot off and replanted. Hopefully it'll take well enough to survive the winter. I assume the other one was able to get out the pot better. Any idea how long it takes for the plant to show whether it's adjusting to its new non-pot life?

Too many variables to answer that but I hope you see signs of perking up soon!

It will not be possible to compare before/after growth as sunlight levels have been decreasing since the summer solstice and the plants will not be actively growing in the fall and in winter if overnight temps are below or markedly below 50°F.