Czech naming of these imposing perennials is not yet fully established. Name rozrazilovec is preferred members of the Czech Association perenářů. But you can also meet with the designation speedwell (due to their close relationship with this family) and also with počeštělým term veronikastrum, though it does not name exactly twice tuneful… Current botanical concept ranks these plants to the family jitrocelovitých (Plantaginaceae).
It is a vigorous, reliably perennial herbs, growing up without a problem 120-180 cm and some varieties and more. Hence suitable chiefly in the background or perennial Wednesday larger groups, which consists in flower significant dominating feature. They look good in combination with leafy bushes. Their attractiveness is determined by how very prominent, inflorescence of crop different colors, as well as the actual plant habit. They form an upright, unbranched, densely leafy stems with leaves growing up in whorls above the other. Except from this ornamental value also it offers a few other perennials and beautiful autumn color of leaves, which vary greatly in golden color. They grow usually two varieties of the botanical species, a to severoamerického Veronicastrum virginicum and East Asian V. sibiricum. Is sometimes seen as well V. sachalinense with distinctly dark blue-violet flowers, its botanical classification is however uncertain and probably it is only a little larger and stronger form of colored Siberian rozrazilovce.
Plants suits sunny (or. more shade and mild) habitat and breeding, drained soil. Due to its massive growth have a relatively high demands on the availability of water. station, where they are planted rozrazilovce, should never completely dry up. Short-term drought, although relatively well tolerated, But the lack of water relatively quickly react svěšováním and leaves zavadáním. Rozrazilovce nakvétají usually in July and is therefore suitable for flowerbeds and a combination of flowers with ornamental aspect especially summer. Very good they look together with zápleváky (I Helenice), plamenky (Phlox paniculata), zavinutkami (Monarda), třapatkovkami (Echinacea), agastache (Agastache) and of course higher ornamental grasses, such as miscanthus (Miscanthus) or switchgrass (Panicum virgatum).
Rozrazilovce belongs to plants, which frequently attends insects, especially bees, bumblebees and butterflies. Grown product range currently consists mainly varieties with different colors of flowers (mostly in shades of pink, skin and white colors). Probably best now grown variety is the 'Fascination', nakvétající bright pastel pink flowers and often creates the ends inflorescence flattened bizarre formations, called fasciace. lower, byť stále zhruba 1m vysokou odrůdou je 'Adoration' Also with pink flowers. Dále jsou častěji nabízeny 'Lavendelturm' pale lilac flowers, 'Erica' with dark pink buds and pink flowers, 'Diane' almost white, resp. slightly pinkish flowers, 'Red Arrows' with blue-violet flowers, velmi zajímavý je také kultivar 'Pointed Finger' Flower angled sideways, etc.. Rozrazilovce not significantly suffer from diseases and pests. They can easily reproduce the spring or possibly. and autumn dividing clumps. When planting is necessary to remember, it is a vigorous plants and that they therefore need to leave sufficient space. Otherwise, it is a demanding, long-lived perennials, which certainly deserves more attention.
Unfortunately, I can't advise you this way from your computer. There can be several factors. Veronicastrum usually likes a rather sunny position and may suffer from excessive humidity. But it's really hard to judge like that. You tried them in another place?