One of my outdoor plants – a flowering, climbing vine – started to show some tiny little yellow bumps growing on the vines and leaves. I’ve attached two photos. I’m not sure what these bumps are, or what they mean. Is my vine sick? Are these little bumps harmless? Nearing the end of July and the blooms are only just now starting to sprout – i don’t want to risk my vine’s blooms with a potential disease. Can you help? Based in Toronto, ON Canada. Thank you!
Thank you for contacting Toronto Master Gardeners regarding the yellow bumps on your vine.
Your flowering vine appears to be a Mandevilla, a beautiful tropical plant. The infestation on your vine may be scale or aphids. The following article describes the various forms of the scale insect, including a brilliant yellow form, and supplies directions for eliminating the pests. A small infestation may only require that you gently scrape them off with your fingernail.
If the insects are aphids, and they come in a yellow form too, they pose the easier remedy of removing them with a strong blast of water from your hose.
Good gardening practices includes monitoring your vine regularly to identify any pests or disease that may occur since early detection is key to maintaining plant health. Little nooks and crannies are favourite places for the plant pests to hang out, such as where the petiole, or leaf stem, attaches to the main stem, and on the undersides of leaves particularly next to the main or lateral veins. This sleuthing is particularly important before you take your tropical plant indoors where there are no natural defences such as ladybugs or other beneficial insects.
An earlier enquiry regarding scale on a houseplant will provide good information about control of this problem: http://www.torontomastergardeners.ca/askagardener/scale-on-spider-plants/
We wish you luck with your lovely vine.