This genus varies all the way from a filmy surface mat in some cases to plants growing 5 or 6 feet. Generally speaking they are, and this applies to varieties of V. teucrium. V. ‘Crater Lake Blue’ makes a brilliant show in June-July, barely 12 inches high, and V. ‘Shirley Blue’ is only 6-8 inches. V. ‘Blue Fountain is taller, up to 2 feet, all flowering at about the same time. One of the earliest is V. gentianoides which has light blue spikes to 2 feet in April-May, from bright green mats, but V. spicata incana is grey leaved with 1 foot spikes of violet — less free than the slightly taller V. ‘Saraband’ and the rather untidy grey leaved V. ‘Wendy’. These flower from June to August and need well drained soil. V. longifolia ‘Foersters Blue’ is a deep colour, the spikes coming on bushy green leaved plants 2!/2 feet high. Much taller, later, and lighter in colour is V. exaltata. In August and September this has 4 feet spikes on which saw-edged green hang. The most imposing tall is the white flowered V. Virginia alba. The spikes run to 5 feet tapering gracefully with whorled , and strong enough to resist any gale. There is a blue and a pale pink V. virginica, but V. alba remains effective for longer during late summer. Apart from V. incana and those in its group best planted in spring, Veronicas can be planted at any time when dormant and are generally long lived and trouble free.
VERONICA teucrium ‘Crater Lake Blue’