This time I’m giving you the good news first: the Northern Gold Forsythia is a beautiful, yellow flowering bush that is fully hardy. It blooms first in spring and grows about 7- 8 feet tall and wide. It has good soil tolerance, is fast-growing and the fall colour is a mix of muted gold and burgundy. The branches can be clipped like pussy willows and placed in jars to bloom indoors if cut in early spring.
Now for the bad news. Although the shrub is fully hardy, the flower buds are a little more sensitive to the extreme cold. In mild winters, the entire bush lights up in spring. In tough winters, if the shrub is exposed to north and west winds, it will not bloom except below the snow line. I’ve seen shrubs at the Morden Research Station bloom consistently each spring – but they are placed in Zone 3b while most of southeast Manitoba is Zone 3a or a little less towards the Ontario border. This means that Morden’s minimum temperature is generally between -30 and 34 Celsius each year whereas our area will go down to -36 to -38. Sadly, this causes shrubs like this Forsythia and the Double Flowering Plum to lose their flower buds more often than not. We can however improve those odds a little by planting shrubs like this on the south or east side of a building, supplying ideal wind protection from both the north and west sides. Planting areas inside corners facing southeast or even a large fence providing the same protection can significantly improve the blooming potential. Some winters are just harsh, and we won’t see the flowers but many people still think it’s worth growing these plants because of the spectacular show they put on during the good years. The benefit of course is that they seldom have structural damage from the cold. So, you still get healthy greenery out of the deal.
However, the flower sensitivity can be used to an advantage. If you need a hedge that will grow in the open exposure but you do not want flowers like lilacs due to allergies, planting a forsythia is a better option. The greenery will make for a good, dense hedge and can be easily pruned through spring or fall. The flowers will have next to no chance of blooming in such a windy spot, there would be a few persistent ones that may survive near the base. Allergy issue averted. If you like Ironclad go with a lilac or honeysuckle for a large shrub. If you want something a little more unique, consider weighing your odds.