Question
My nasturtiums are very full, but the leaves are often yellow throughout the flower bed.  do they need Acid feeding?

Answer
It is highly unlikely that your garden soil is so acidic your Nasturtiums cannot thrive there without help from you.  More likely your soil is not up to par.

Quality soil needs good TILTH for flower roots to grow.  Good tilth comes from lots of organic matter -- compost, Bonemeal, humus, peatmoss, manure of all kinds.  Earthworms contribute to good tilth.  Adequate moisture even plays a role by maintaining the comfort zone of microbes there.

Top dress your poor Nasturtiums with something delicious like Alfalfa Meal or Kelp.  Scratch it in VERY lightly to avoid wrecking the frail roots, and apply some water.  Fertilize with organic mixtures and compost tea.  Take good care of your Nasturtiums by taking good care of your soil.  In the fall, when blooming is finished, get a hand tiller and mix lightly some dead brown leaves and Grass along with that organic matter listed above.  Next spring, plant Nasturtiums again.  They'll grow much better.

Acid feeding now I believe would not be a wise choice of action.

One more thing: Check the leaves VERY closely, preferably with a magnifying glass, and see if you can identify any pests on the undersides.  Spidermites are a dry weather pest that run rampant in the middle of a Summer Heatwave.  Humidity is their foe.  Shake a piece of white paper under a few leaves and shake the paper just to make sure nothing falls off and moves.  Spidermites are VERY tiny.  You probably won't know they're there unless you have a magnifier.  If you do, let me know.  But still, you should fertilize and amend properly.

rsvp