Although they are showing similar symptoms, the ailments of the zinnia and blackberries are probably unrelated or only partially overlap. Are the blackberries being grown in containers? If so, and since you mention the zinnias are grown in containers, are you completely replacing the soil each year, or re-using old soil from the previous season? Are the pots sited in full sun, where they receive a minimum of 6 hours of direct light a day in the summer? Do they have good drainage, where there are unobstructed drain holes in the base of the pot? (For example, there's no gravel in the pot base, and they don't sit on saucers.)

If symptoms appear again this season on the blackberries, you can compare them with the information on our Raspberry and Blackberry Diseases page and the insect borers on our Insect Pests page. Preventative treatment recommendations, where applicable, are mentioned in those listings. If you aren't certain which pest or disease symptoms you are seeing, feel free to send us more photos. The included photo (from last year?) isn't too diagnostic, unfortunately. Leaf spotting could be due to fungal infection, but yellowing between the veins might be viral, due to spider mite feeding damage, or even due to a nutrient deficiency. Has the soil where they are growing (if grown in the ground) been tested by a soil testing lab in recent years to check for pH and nutrient levels?

Zinnias can contract a bacterial leaf spot, which tends to infect and kill the lowest leaves first, working its way up the stem. There are also several fungi which can spot zinnia leaves as well, though not necessarily the exact same ones affecting the blackberry. Spider mites and leafhoppers can also feed on zinnia foliage during summer, causing discoloration, as will a nutrient deficiency depending on how plants are fertilized. Some cultivars of zinnia have improved disease resistance, so you might want to switch to these this year to see if they fare any better. (Seed catalogs and plant tags should mention this if it applies to the variety listed/tagged.) If you have been re-using potting soil, replace it completely with fresh potting mix after giving the pot a wash or wipe-down with disinfectant (make sure to rinse well) to remove soil residue that might be contaminated with infectious spores.

Miri

Hello Debra,

Eight hours of direct light should be fine, so that's good. Soil testing for the blackberry bed would be useful, and you can share the results here if you would like guidance on what the results mean. The leaves do look smaller than they should be, so maybe the plants are crowded, need selective pruning, or something else is going on.

We suggest not treating plants with neem yet since we do not know what issue the plants have. Pests and diseases should always be identified prior to beginning treatment; plus, not all conditions are treatable. Even though it's organic, neem is a contact and broad-spectrum insecticide (and occasionally, a poor fungicide) and we do not want treatments to negatively impact pollinator and beneficial insects, which any insecticide of this type risks doing. Plus, it's only effective if it comes into direct contact with the insect or fungal spores responsible for causing the damage, so application timing is critical to efficacy. (This is one reason why identifying the causal agent first is important.) Sharing photos of symptoms as they appear this coming season would indeed be helpful in making a diagnosis, and you can attach them to this reply whenever they manifest.

If mites are one of the issues plaguing the Zinnias, then using neem when they appear later this summer should help in that case. Be sure to thoroughly spray all leaf surfaces (which includes undersides) when treating mites, since contact pesticides like neem will not suppress pests they don't reach. In this situation, you can make applications either in early morning or early evening to avoid spraying pollinators visiting the blooms.

Miri