Growing Rudbeckia Treasure Trove

Jessie Cumber, Walters Gardens

Rudbeckia Treasure Trove is a prize worthy of pursuit. This botanical bounty will shower you in an explosion of golden flowers and it will bloom from mid-summer to early fall, providing you with months of color. It has bright yellow/gold petals with a dark brown center. 

The Black-Eyed Susan is a native plant to North America found mostly on the eastern half of the United States and in southeastern parts of Canada. Treasure Trove is hardy to Zones 4 to 9 and can grow in areas that are full sun to part shade. 

What makes this rudbeckia so special is that it’s highly resistant to Septoria Leaf Spot in comparison to other varieties on the market. Throughout six years of outdoor trialing in West Michigan the plant saw no damage. 

Rudbeckia Treasure Trove packs pollinator power. This plant attracts bees and butterflies into your landscape. Whether you’re using it for a strategic border or creating a whimsical wildflower garden, this plant fits the mold. Treasure Trove can get up to 32- to 36-in. tall and has a spread of 36- to 42-in. wide. Its long stems also make this plant the perfect perennial for cut flower growers to add to their flower fleet.

Treasure Trove is an incredible native plant that can be planted all season long, from late winter to late summer. Rudbeckia can be grown in a large range of different sized containers. Our trials team has grown this plant in every size, from a quart pot to a 3-gal. container. Depending on when you plant the crop and in what size container, it can take anywhere from six to 10 weeks to be retail ready. 

Quarts, trade gallons and gallons planted from a 72-ct plug can take six to eight weeks to grow. These easy-to-plant sizes will fly off the shelves, which is perfect because it’s not recommended to hold on to the plant in these size containers, as Treasure Trove is a very vigorous grower. 

Thirty-ct. plugs are great for 1- to 3-gal. containers. Plants can take up to eight to 10 weeks to finish. For both 72-ct and 30-ct. plugs, it’s recommended to trim the plant once you see the flower stalks at least once, as it promotes good flowering habits and uniformity throughout your crop. You can do this more than once to promote even more branching. 

One- to 3-gal. containers are recommended also when planting bareroots. These plants will finish within six to eight weeks of planting. It’s important to note that when growing in late winter you can expect plants to be on the longer side of these grow times then they would be in the spring or summer.

Rudbeckia Treasure Trove is a perennial that will flower regardless of vernalization. Even without vernalization this plant has a beautiful flower display and great vigor. Vernalizing this plant will increase the bud count and overall size. Therefore, we only recommend vernalization in larger container sizes, such as 2 to 3 gal. You can vernalize Treasure Trove in smaller sizes, but they can become a challenge to keep watered in smaller containers.

In the garden, this plant prefers drained, not overly rich, soil. Keep this in mind while growing in a container, as well. This plant is a vigorous grower that has higher-than-average watering needs in containers. It’s important that your plant maintains a pH between 6 to 6.5. Frequent watering with fertilizer while pH is out of balance can lead to phosphorus toxicity and other micronutrient imbalances. pH management and the occasional application of silica have been found to keep this plant looking perfect at retail. GT