Hello! My Mandevilla is not flowering! I bought it at the beginning of summer and it sits in a place that is shady most of the morning and gets afternoon sun and shade again in the evening. Is it not getting enough light? I water it when it looks dry. Other than the lack of flowers it looks healthy and has grown a bit since I bought it. Any suggestions?
Give it a teaspoon of Epsom salts dissolved in a quart of water. Mine stopped blooming when I repotted it and I had to use the salts to get it started again - the magnesium sulfate helps any plant to bloom.
You might try gradually moving it to an area that gets more sun--it probably doesn't need to be in full blazing sun all day long, but if it's only getting sun for a couple hours in the afternoon that might not be quite enough. Just make sure you adjust it gradually to more sun so it doesn't get sunburned.
Your Mandevilla (Dipladenia) if you want to find out more cultural info, It does need a bit more sun than it is getting right now, they are tropical plants that twine and curl around anything they can touch once they get climbing, they like plenty of water in the growing season and much less after the flowering has stopped, in winter rest time, just keep the soil damp enough to keep the plant alive, you also need to mist the plant almost every day, every second day at the least as they like a humid atmosphere, if your plant is in a pot, check this is not too large or too small, if you have transplanted it since you got it, maybe it is in too large a pot and the plant is making lots of new roots instead of flowers, either way, I give mine a liquid feed every week in the growing / flowering season, but stop in winter when the flowering stops, I am sure your plant really just needs time to settle into a good bright area and grow some more before it gives you it's wonderful cascade of bright flowers. hope this helps you out some and you can begin to enjoy this lovely plant, (incidentally, I have to grow mine as an indoor plant here in UK) do watch out for a milk sap that comes out from the stems if you prune or break any of the foliage and dead head all the time once it starts to flower. Good luck WeeNel.
Thank you WeeNel! Is Miracle Grow an appropriate liquid feed? I think the pot may be a little big. It has seemed to grow much more in the past couple of weeks. And I have moved it to a much sunnier spot - I am gradually moving it to more sun. Right now it is mid-90's (Fahrenheit) and sunny most of the day - daily watering is probably best, or is that too often?
Hi NewTX, Miracle grow should be just fine, but to start it off, I would give just a half strength doze for the first couple off watering's, watering everyday should not be a problem in your temps IF the pot has good drainage and dont let it sit in a sauser of water for longer than say half - one hour, also in your temp, it will help the plant if you mist it so the foliage can enjoy the humid conditions these plants like, because these plants have a very glossy foliage, it should be safe to mist in the early evening before the temp drops (IF it does) but try not to mist when there is strong sun on the plant as the droplets of water can act like a magnifying glass and CAN on occasions cause the sun to scorch the leaves when loaded with the misting, I try to also mist under the foliage so aim the mister upwards also. NOW that you have re-potted the plant into a larger pot, I would think your problem with a slow start to the growth has just been the plant needed time to settle into it's new compost and has been busy making roots at the cost of new growth, but as you now see the plant staring to grow again, you should see it just take off, my plant never flowered the first year I got it, early spring, it just went wild. to make the plant more bushy, you can if you like, pinch out the growing tips and this will make the plant send out more side shoots,watch out for the milky sap that comes when doing this, it wont harm the plant at all but for some folks, it just might cause irritation to your skin, so wash your hands after doing this. I have my plant growing up a tee-pee frame made from garden canes as they do get climbing when they start growing, but they also look good twisting and climbing up one of the store bought obelisks etc, the trouble is, in a couple of years growing, you wont see the frame anyway. Hope this helps you out and you soon start to really enjoy your plant. Good luck. WeeNel.
On the watering, I would check first before you decide to water every day. In the TX heat many containers will dry out fast enough that they need water at least once a day, but if your pot's a little big for the plant, then the plant may not go through all that water in one day and then you could end up overwatering. Next time you were thinking of watering, I'd stick your finger down a few inches in the pot and see how things are feeling--if it's really dry then go ahead and water, but if it's still feeling wet then you ought to hold off.
I have a time release 3 month fertilizer on my plant and then I hit it once with the epsom salts in June. It gets light shade in the afternoons (it's in front of a small Maple leaved Hibiscus) because it's really hot here in the summer, temps in the 90's and 100's in July and the pot is clay and dries out too fast. It likes the soil dry so I only water it once a week if we don't get rain.
Hi Dragonfly, you have prob got the better ideas for this plant then me because you seem to have the same temps almost as NewTX, but what is good in one area will vary slightly to another due to soil, pot size and as we said, light or shade, but I have to grow tropical plants indoors and try to mimic the conditions they like when they grow in there natural habitat, and most times we are OK, but if you have yours outdoors in simmiler conditions I would say the wise thing to do is follow your methods, when plants are in pots and you find a problem, it is a lot easier to adjust there needs, and change things for them so thanks for your info, I really wish I had all your temps as tropical plants are my favourite, probably because they are a chalenge for me here in UK, all our pots dry out really fast either by wind or sun, or in my case indoors, too hot summer temps or too cool winter, hope NewTX gets hers off to a good start so she can enjoy the lovely coloured blooms she so wants. good luck. WeeNel.
WeeNel, the mandevilla is too tropical for me to leave outside, I'm only in climate zone 7 which means that we have mild, short winters but June and July are brutal, with temps in the 100's every so often and the sun heat is intense. Dallas is actually a zone hotter than me, zone 8a so NewTX will have to keep an eye on her plant in the sun. My mandevilla loves the heat but it's in a clay pot so it dries out quickly, that;s why I give it afternoon shade..
I always thought that the temps in Scotland didn't get very high in the summer, maybe high 70's. is that true?
Miracle Grow might be causing more leaf growth and less flower formation. You might want to try a fertilizer made for flowering plants (petersons, or osmocoat) and see if that helps, but more than likely it is stalling because of insufficient light. Are you going to overwinter your Mandevilla? If so, I would give it it's last feeding before the middle of Sept. If you let the vine go almost dormant in cool conditions for the winter, then cut it way back in the spring you should get a ton of flowers next year.
WeeNel, I like your idea of growing it up a tee pee. When you say "garden canes", do you mean bamboo poles?
I would like to know what I am supposed to do with this plant in the winter? I live in Zone 4/5 but have a 1000 watt metal halide for indoor stuff...would this mandevilla be a good candidate for the halide area? I got it as a seedling this spring & it is just now blooming good...it won't be long before a decision has to be made.
For me, what works best is bringing the entire plant into an unheated room in my house or basement. I don't cut it back yet unless I have a shortage of space. Cutting it back signals the plant to put on new growth. I let it go dormant, very LITTLE water, no food and low temperatures. This will cause almost all of the leaves to fall off eventually. You will think the plant is dead for sure. In the spring, I wait until temperatures are reliably in the 70's and bring it back outside. At this time I cut it back to about 3 feet, feed and water it, and put it in a bright spot with no direct sun. In a few days you will notice new growth. After a week or two, I move it to almost full sun and in no time it is flowering like crazy. Most people will repot in the spring, but I have had mine in the same pot for 7 years now and all I do is topdress a little each year. Repotting seemed to slow down the flower production considerably. I let mine climb an old bamboo fishing rod and it gets very tall by the end of the season. Once it resumes flowering, it blooms like crazy until I bring it in. There has to be over 200 flowers on it at any given time. Mine is Red Riding Hood, so the flowers are not as large as the pink mandevilla that I assume you have. I wish I knew more about the metal halide question you have. I know someone will be able to help you with that soon. I'm going to watch for the answer. Maybe that's a better way than the one I described.
Hi dragonfly, you are right about the temp, we are all suffering from heat exhaustion on the odd times the temp goes to over 80's and even though most of my garden loves this, our veg types dont and withing 2/3 days of this, the veg, or a lot of them will run to flower, most of the type we grow are for the cooler temps like Brasicas, but carrots, Parsnips and beetroot ect will manage this fine, it all depends on what stage the veg are at when we do get the occasional heatwave, if still very young, they will be fine, but if quite far on, forget it because right after the heat, we could get temps drop down to 50-60 over night,
As far as tropical plants go, I have a large greenhouse and a nice conservatory where I grow tropicals, so even when the temps are 60-70, the sun shining through the glass can cause more damage than good, the heat inside can reach to over 90 /100 and that means I have to throw every window in the side and roof wide open, I then throw buckets of water onto the floor to help humidify and cool the area down and also drop the blinds down, I know it sounds like a lot of work, but I dont know any other way to do things as we are so used to such fluctuating temps, the worst thing for me is high winds with added salt spray as I live right atop a cliff wall by the ocean and there is no protection from the high winds and in Autumn/winter I can have the foliage stripped off my shrubs or young trees over night, now and again thats fine, but last 2 years we had gales and heavy rain from about September right through till March/April, so that really was a testing time, indoor plants and tropicals are fine because they are sheltered and if really cold I have a heaters for emergency's, but the days were very dark and I suffered lots from lack of light even in early spring for normal germination, but you know what, being a gardener means you just have to learn to live with it and use all your energy sorting out all these problems when they arise.the up side, we never suffer from lack of water and I can water any time I like, evenings or mornings, it dont matter here. you take care and good luck. WeeNel.
The main problem for the Mandevilla when inside is you need to make sure you mist it as they do like humidity when in a dry heat especially indoors, but in winter, you would have started to let it rest and I cut back on misting then as the temps here are cooler and it seems to survive the colder temps as it has stopped growing, but if in centrally heated homes you need to make sure the foliage dont get too dry. good luck. WeeNel.
Thanks everyone, I have gotten some great tips! I think my mandevilla is happy in a bit more sun and is staying watered. Hopefully will see some flowers soon. I read through all the posts and saw some info about wintering. What is the lowest temp that the mandevilla likes. When you all talk about cutting it back - do you mean cutting off all the limbs so you basically have the main stalk? Is it possible to trim it back to talk it into the house and enjoy it in a sunny room? Any suggestions on that?
Yes, you can bring it in and put it in a sunny room, but it has to be direct sun in order to keep flowering. Others may have different experiances with Mandevilla, but mine has been that given a winter dormancy period, it will flower much better the following spring. Another problem w ith keeping a mandevilla going through the winter is, almost without exception, they get mealy bug or spider mites from the warm dry air inside your home. Outside, they can be hosed off regularly, but inside they get watered at the base of the plant and pests love a dry leafed plant. I would suggest that you take cuttings to root and then go ahead and bring your plant inside. That way, if things don't go so well, you will still have a mandevilla to put out next year. You might also want to keep the inside plant misted well. It will be greatful for the mositure.
As for the question about the minimum temp. for mandevilla, I'm not certain, but I would guess about 40 degrees won't kill i t, but I doubt you would see any new growth at that temp. Lastly, when I cut mine back, I wait until spring (so that I don't signal new growth) then I cut it back by about two thirds. You could cut it back to as little as six inches, or leave most of the plant intact and it will do just fine. I prefer a bushier, more compact plant so I cut it back to about 30 inches. Feed it 1/2 strength fertizer and make sure it's getting at least 4 hours a day of full sun and you should have a great looking plant in no time!