Hello,

It seems like you might dealing with cedar apple rust, which is very common in Colorado, especially where junipers and crabapples are planted close together.

This disease requires both hosts to complete its life cycle, moving from juniper to crabapple and back again. Because of that, even if you removed your original junipers, nearby junipers in the area can still contribute to infection. Complete elimination is difficult, but management is very possible.

You do not need to remove your crabapple. If you would like to keep it, there are a few effective approaches.

Fungicide treatments can help protect the crabapple. These are preventative, not curative, so timing is important. Applications should begin right as buds start to open and continue through early leaf development, typically every 7 to 14 days depending on the product and weather. Look for products labeled for cedar apple rust with active ingredients such as myclobutanil, propiconazole, or chlorothalonil.

Pruning can also help reduce pressure. If you see galls on nearby junipers, those can be pruned out before they produce spores in spring. On the crabapple, remove and dispose of heavily infected leaves or branches if they appear later in the season.

Maintaining overall tree health is also important. Providing adequate water and minimizing stress will help the crabapple tolerate some level of disease.

Your new Woodward junipers are still susceptible, so some level of disease cycle may continue over time.

Timing may vary slightly depending on your elevation and spring conditions, but applications should begin at bud break and continue through early leaf development.

Please feel free to reach out if you would like help with product selection or timing for your specific conditions.