Guava Troubleshooting

Hey There! I’m new to Gardeners Corner and have come in search of help for growing guava indoors. I’d be grateful for any advice on diagnosing some issues I’ve encountered- namely what I think may be leaf spot. And also, treatment options. I’d be really devastated making a wrong diagnosis and harming them. I have 14 guava trees total and a couple are over 5 ft. tall and they are approximately 2 1/2 years old(started from seeds).
I have loads more questions, but I’ll start with this first! Thank you in advance!

 

Looking at picture one I'd say chlorosis, but looking at the older leaves it looks more like insect attack of some kind of leaf sucking pest.

14 trees in the house seems like quite a lot.

 

Ha ha! Yes, it is a bit of a jungle in the sunroom! Thank you for your quick reply. So, if it’s chlorosis, I’m looking at amending the soil. I thought it could be insects as well, but absolutely no sign of an actual bug- even when I used a magnifying glass. No webs, sticky residue, etc.
All plants, unfortunately are affected. I live in Canada and our winters are very dry, so I took to misting them twice a day to increase humidity (was about 32%)
I thought I perhaps created an environment ripe for a fungal infection. They were grouped quite closely and I suspect air circulation was not great.
I’ve been playing it safe with a 1-1-1 miracle gro fertilizer once a week.
So maybe this could be a possible cause for chlorosis?

 

Are you able to move them outside in the summer months?
For chlorosis I usually use an iron feed, you can get a seaweed feed with added iron over here in UK, not sure what's available over there.

I think you are doing the right thing misting, the leaf spot doesn't look fungal to me, as long as it doesn't get any worse I wouldn't be too bothered about it, it could well just go away once the summer comes and the plants can get more air, hopefully.

 

Hi Glenda75, welcome to GC Lucky you having access to Miracle-Gro! I've never found a better fertiliser. @pete is right though about the plants needing something specific for ericaceous plants to correct chlorosis. Perhaps @CanadianLori could point you in the right direction for what's available over there? I'm intrigued by your description and photos of guavas....there are quite a few different plants that go by that name. Could you elaborate with the Latin name perhaps? They don't look like Psidium or Feijoa

 

I recently used a new organic plant fertilizer that I didn’t realize was seaweed- lol! The ingredients listed are: Ascophyllum nodsum, potassium hydroxide. It doesn’t have iron added, however. I’ve only watered the plants once with it. But now that you said to try seaweed fertilizer, I will continue using it.
I have thought about putting them out for the summer, but I worry about the other houseplants I have when it’s time to bring them back in for fall and introducing pests.
They receive a lot of light , as they face south west in a sunroom.
I wish I could tell you what variety they are, but it was my daughter who planted the seeds from guava she bought at the grocery store.
I was entrusted with their care while she went to The Netherlands to pursue her Masters in Plant Sciences in 2021. Sadly, she passed away unexpectedly and ever since then, I’ve been trying my best to keep her guava trees thriving and healthy. So they mean a lot to me and hence the extra precaution around their care. I’ve been scouring the internet for help and you’re the first person to respond with suggestions. So, a big thank you! I am eager to try the seaweed. I also am curious as to what kind of guava they are.

 

I am sorry to hear about your daughter, I can see why you want to look after them well Looking on the 'net, it looks like Psidium guajava. Here's a link to varieties available. https://fr.search.yahoo.com/search?fr=mcafee&type=E210FR885G0&p=guava+fruit+canada

 

I tend to think that at some point you may have to concentrate all your efforts maybe on just a couple of plants, they are likely to get too big.

Pot size could become a problem at some point as well, it would be interesting to know what size pots you have them in now and how big the plants are.
I definitely think that they will benefit from a period outside in summer if you can.
Maybe in a slightly shaded spot when they first go out and not in intense sunshine.

 

@Glenda75 the best shops for buying soil amendments and fertilizers are, for liquid additives, hydroponic shops and for other amendments, and if you live in Ontario, Ontario Growers Supply | London | Ontario.

Canada is a big place with a LOT of growing zones so if you have time to update your profile with your general location it would greatly help people to offer advice appropriate to your environment.

It's nice that you have a sun room. It is this time of year that I realize that I simply do not have enough bright window space for all of my seedlings!

 

Thank you @CanadianLori - the website you directed me to had way more product options than I have found so far. I live in Zone 3. Thank you @noisette47 for the link- that’s the best one so far as it has a picture of the leaves to go with the variety- definitely think they are Psidium guajava after looking at the photos.
I know one day I’m going to have to put some of these guys up for adoption as they are filling up space rather quickly. I just went up to 8 inch pots this past summer. Interestingly, they don’t seem to have a big root system. I plan to increase pot size again this summer.
Some further background on what I have done with them: I placed leca balls at bottom of pots to increase drainage as well as threw a handful of leca and mixed it in with the potting soil (just a regular houseplant potting soil). I only water them with distilled water as I’ve heard salt will build up around the leca if I use tap water. I did supplement with grow lights for winter when our hours of sunlight were greatly reduced. However, the taller guava quickly surpassed the height of the lights and I had to stop using the lights due to the upper leaves getting damaged.
After you queried about pests, I did a thorough inspection again. I never see anything, but I took a picture of what looks like lint? It doesn’t move and I’ve searched everywhere for a pest that matches. I took a couple pictures with a magnifying glass over the camera lens. Thoughts? I’m also providing some pictures of the plants in general so you can get an idea of size, etc. Apologies for the long post, but you guys are giving me great advice and hope that I can figure out what is going on with them! thank you so much

 

I think the white thing is the insect case were the adult has emerged from.
It could be thrips, you might find this interesting.

 

Welcome to the forum @Glenda75 . I have some cousins in Edmonton and I've never met anyone from that city who wasn't a really nice person!

 

Hey there- I have been using the seaweed fertilizer for a couple weeks now. Things are still not going well. I think their condition is worsening. New leaves are coming in distorted and many leaves starting to dry up despite moisture in the soil. I’m beginning to think something is very wrong with the roots ( nematodes?) any idea where I could send photos to horticulturalist to help identify the problem?

 

The sea weed feed could take a while to work, I hope by using it you are not being tempted to overwater.

I'd not be all that bothered by the leaves being slightly distorted, its the colour of them that would be my biggest concern, they look thin and yellow.

I'm tending to think, looking at one the earlier photos, that they have grown up and getting past the top of the window, so they are not getting good light to the growing points.

 

Thank you @pete. I will do my best to remedy the lighting situation. Any thoughts to that swelling at the base of the trunk? It’s only the one plant. Also, the directions on the seaweed said I could use with every watering. I only water when the plant pot gets very light- I lift them to check. Usually water twice a week as the sunroom is very warm during the day and I think because the leaves are so huge, they use up a lot of water.
So, in your opinion, you don’t think they are in dire condition?