Not flowering

[lash]

I bought a Lithodora Diffura and a jasmine among other things last year. They had lots of nice flowers last year, but through this summer, not a single one. I've fertilized 4 times during summer, and watered regularly, and they are fully exposed to sun (as last year). What could be wrong, and what do I need to do in addition?

[rainbowgardener]

it always helps to tell us where you are located. There are hardly any garden questions that can be discussed without regard to location/ climate. Pictures would also help us get a better sense of what might be going on with your plants.

Here's what they say about your purple gromwell (Lithodora):

Plants MUST have a well-drained, acidic soil in order to thrive. Heavy clay soils are sure death. In colder regions this will benefit from a light covering of evergreen boughs as soon as the soil is frozen in late fall.
https://www.perennials.com/plants/lithod ... -blue.html

If you don't know your soil pH, you have to have it tested. I well know because where I was until recently had alkaline clay soil. Any acid lovers I planted, no matter what I did, would not thrive and would eventually over a few years die a lingering death.

What are you fertilizing with? Fertilizing four times seems like a lot to me (since I don't use synthetic ferts). If you are using a high Nitrogen fertilizer, that can be adding to the problem. High N ferts favor lots of big leafy growth at the expense of flowering.

[lash]

Thanks!

I live in Berlin, Germany.

I'm not quite sure to translate the fertilizer. It's name is "DE BIO Universal Liquid Fertilizer." It contains:
1.0% sulphur
1.6% natrium
0.2% magnesium oxide
22% "organic substance"
0.5% nitrogen (ammoniumstickstoff)

By the way, the plants are in flower pots (balcony).

[rainbowgardener]

Oh, you didn't say they were in pots.

Lithodora is a ground cover that grows by spreading. How does that work in your flower pots? Are you growing it just as a trailer, trailing down over the pots? Did it bloom at all this year? They only bloom in spring time.

I don't know enough to know from your description about your fertilizer. But you want to be looking for fertilizer for acid lovers:



look for fertilizer for azaleas, rhododendrons, etc. That will provide the acidic environment your lithodora needs.

Your soil may also be staying too damp for it. A cactus mix or amending your soil with part cactus mix might give it the well draining environment it needs.

It is a full sun plant. You said it is in full sun, but then you said it is on a balcony. A balcony is never full sun, since there is a building behind it. What direction does your balcony face and how many hours does it get direct sun?

Just because they were flowering well when you bought them last year, doesn't mean they really like your conditions in the long term. You have to provide what they want.

Did you repot this year? How big are your pots? (Pictures would still help). I had a jasmine that grew like crazy and never flowered. When I took it out of the pot, I discovered the pot was so full of roots there was hardly any soil!