Up for sale is one pack of 30 Black Hollyhock seeds (Alcea Rosea nigra). Perfect for summer blooms these hollyhock create a spectacular single petaled black to very dark red flowers on 60" stems. Very hardy in the garden and also make a great cut flower with a long vase life.
We offer flat rate combined shipping on all orders, no limit on the amount or type of seed packets.
Soil temperature: 55 - 60 degrees fahrenheit
Germination lighting: Light
Germination days: 10 - 12 days
Plant spread: 24 inches
Plant height: 60''
Plant type: Biennial
Maturation days: 80 days
Considered a biennial Hollyhock will only flower for one full growing season. The best way we find to grow hollyhock is to sow these directly in your garden from late summer until early fall where they will flower the following spring. Hollyhock will not germinate in cool temperatures and need several days of temps in the 70's to germinate. The biggest mistake people make with hollyhock is to try and germinate the seeds in early spring before your soil temperatures have warmed up to at least 60 degrees (night time soil temperature). If sown in cool weather the seeds and will rot before they have a chance to germinate.
Work enriched garden soil 6" deep and scatter your seeds and then top with a light dusting of compost or peat. Another mistake made with holly hock is by sowing the seeds too deep as they need light to germinate. The seeds will germinate, and develop roots over winter, and flower the following spring and summer. The last picture is a hollyhock that is about 30 days old that direct seeded in the garden on October 1st here in zone 7.
If you get a late start, and want to germinate them in late fall, start them indoors in 4" pots using germination heat mats (or other heat source) to get them to germinate. Once they have their second set of leaves, and are about 2" tall, transplant them into the garden as they send down a tap root and if left in pots will become root bound and not develop correctly.
You can also start these in winter indoors about 8 weeks before your last frost in spring in 4" pots. After your last frost in the spring transplant them into your garden and they will bloom flowers a little later than fall planted hollyhock.
Finally you can also sow these in the spring directly in your garden. They will germinate, and grow, but will probably not bloom until the next spring and summer.
Once hollyhock have had a full growing season of blooming flowers they are done. They will die back at the first frost, and some will try to come back the following spring, but they will not be very productive. If you let flowers stay on the plant they will self seed and create new plants the following spring but once their seeds drop it's best to pull the old plants up as they will not re-flower.
A quick note about hollyhock and a fungus called Rust. Hollyhock are very susceptible to Rust and we recommend you dust your garden area (after tilling your soil) prior to sowing your seeds with dustable sulfer, which you can get at any home improvement or garden center. In zone 7, in mid march about a month before our last frost, we dust them again just to make sure we don't have any problems with Rust during the summer.