Fielding Questions: Overwintered dipladenia, bleeding birch, covering grass seed and more
Q: I'm thrilled to see my dipladenia full of buds. Thank you for all the good advice. — Karen Westrick, Fargo.
A: Your dipladenia looks beautiful and ready for another summer outdoors.
Your budding plant demonstrates how outdoor patio plants like dipladenia, mandevilla, geranium and others can be brought indoors before autumn frost, wintered in a sunny spot and then returned outdoors in spring for another growing season. Tips that you might have followed include pruning the plants slightly when bringing indoors, giving a heavier pruning in March to remove winter’s weak growth, repotting in spring if needed and using water-soluble fertilizer every two weeks beginning in March.
Q: How can one stop the water bleeding from a birch tree after a large limb removal? — Charles Salmela.
A: Although it might look alarming, sap bleeding from a birch that’s pruned in spring can be expected. It’s not going to harm the tree.
Birch and maple both bleed large amounts of sap in the spring from any opening, which allows maples to be tapped with spigots to let their sap flow into containers for maple syrup. Birch, while not as sugary, can also be tapped, and the sap is sometimes marketed as “birch water.” Native Americans are said to have drunk the sap flowing from birch as a spring tonic.
The best way to stop birch from bleeding when pruning is to delay the pruning until after the leaves have fully expanded, when sap flow slows. The sap currently flowing from pruning wounds should be allowed to stop naturally. Efforts to cover wounds with paint or sealers can inhibit healing, as found by university research.
Q: Must we cover new grass seed with soil? — June and Dean Edmunds.
A: Grass seed, especially Kentucky bluegrass that is a major ingredient in our lawn mixes, germinates best when exposed to light. Covering with soil can inhibit germination. Grass seed is best applied to the surface of the soil, and lightly raked. When finished, you should still see much of the grass seed laying on the soil surface. To help keep the seedbed moist, a light layer of straw, dried grass or much can be sprinkled over the surface, but it should be lightly spread, so you can still see a little soil through some of the mulch particles.
Q: A friend gave me a couple of buckeye seeds to plant. The seeds came from an area tree, and should be adapted. The shells have cracked opened and they’ve started to sprout. Where is best to plant them? How deep, and what sunlight conditions would be best? — Scott Bundy, Deerwood, Minn.
A: The Ohio buckeye seeds should be planted very soon in their permanent location. Plant them about 1 inch deep, and water well after planting. It's a good idea to put wire mesh protection around the spot to prevent squirrels from digging them up, and to prevent rabbits from chewing off the newly emerging seedling trees. Plant where you would like a large shade tree. The seedling will do best if planted in a spot that receives full, all-day sun, or at least six hours.
If you have a gardening or lawn care question, email Don Kinzler at ForumGrowingTogether@hotmail.com. All questions will be answered, and those with broad appeal may be published, so please include your name, city and state for appropriate advice.