Rosa multiflora nana perpetua. Garden Party is a delightful little mini rose that is easy to grow from seed. It’s a tiny mini rose that is suitable for containers, edging, bedding, and rockeries. Perennial roses that bloom over a long period in shades of pink, rose, and white. While most roses are fussy to grow from seed, with unpredictable results, in our experience Garden Party does not require any special conditions to germinate. Speed and evenness of germination may be improved with vernalization. That’s planting the seeds in moist soil, and then refrigerating the planted pot for ten to twelve weeks. This simulates a winter chill, and tends to cause the seeds to all germinate at once. Without vernalization, the seeds may germinate just fine, but over a period of several weeks. Sow the seeds between January and March, and you’ll even get flowers the first year!