Why are my nasturtiums looking sick?

[Catnipmanor1234]

Can anyone tell me why my nasturtiums are looking sick; in that they are curling up as if they had been sprayed with something toxic - they haven't.  Been reading a little about them and think that maybe I shouldn't have fertilised them, which I did about 2 months ago with Dynamic Lifter. The soil is clay, but I put down sugar cane mulch regularly to keep weeds down, and hopefully to improve soil, but the soil has always been 'ratty'. I'm wondering if I should be watering them more. What is a good amount of water for them? I don't want them to become waterlogged in the clay soil. They are in the front garden, which faces west. And the seeds are oldish, and what I do is when the plants are finished, I gather the seed pods, and when dried out (or before) just throw them back on to the soil. Seems to have worked, until the last month. Thanks for your advice, in advance.🦄

[EricL · Accepted solution]

Hello @Catnipmanor1234

Thank you for sharing your question about your nasturtiums. Some of the symptoms of too much fertilizer are yellowing and wilting of lower leaves, defoliation and browning leaf tips and margins. Leaf curling, on the other hand, is sometimes caused by heat stress or insect and fungal infestation.

I suggest looking carefully at the leaves and observing if there are any black bean aphids. They infest the stems and bottom of the leaves curling and distorting them. Another possible cause is too much watering which causes root rot and makes the leaves curl upwards. Nitrogen deficiency is another cause, you'll notice that new leaves come out healthy but the older ones start to curl.

To treat the aphids, I suggest using Eco-Organic Garden 100ml Eco-Neem Concentrate. Please make sure to spray both at the top and bottom of the leaves. In regards to watering, I suggest checking if the soil is waterlogged, if it is, change your watering schedule to let the soil dry out. Check that your pot is draining properly. Carefully dig around your plant and see if the roots are infected with root rot. If neither of the two symptoms is present it could be a nitrogen deficiency, I suggest using Richgro 2.5kg Organics Nitrogen Growth Booster or similar.

Let me call on our experienced members @Noelle and @Adam_W for their recommendations.

If you need further assistance, please let us know.

Eric

[Noelle]

Hi @Catnipmanor1234 

Nasturtiums are generally as tough as old boots but they do not like wet feet - much better they are on the dry side rather than the soil being too wet. Generally they are quite "unfussy" - almost weed-like in their vigour and ability to tolerate a wide range of conditions and soil fertility.

I think Eric is right in suggesting it could be pests or a slight lack of nitrogen. Give his advice a go and they'll probably respond well.

[Catnipmanor1234]

Hello. Many thanks for your reply -  I appreciate it. Well, from your information, I don't think it has anything to do with using Dynamic Lifter, as I've used that in the past.  I'll have a go at your first recommendation - re. black bean aphids and see what I can find. I'm just wondering if all the wet weather we've had this year, could that have caused this peculiar problem?  I've been watering, because the ground is very 'clayey' and gets very hard. - so maybe I've been watering too much, and the previous wet weather period, and my watering may have had a detrimental effect. But first, I'll look for the aphids. I guess that they are 'black'?  And would the remedy for this be harmful to birds, and little skinks (as well I've got blue tongue lizards, coming and going) as I feed the birds, and they have a lovely time scratching around in the sugar cane mulch, which is where most of the nast. are. Thanks for your time. Gabrielle.

[Catnipmanor1234]

Hello, Thank you for taking the time to reply.  I'll certainly follow the first suggestion, and look for aphids. I must say, that this is the first time I've ever seen this sort of 'leaf curling'.  I love nast. as they are such a good ground cover, and with all their flowers, the bees certainly come around - hooray. Thank you again, for your time. Gabrielle.